3:1 "And to the angel of the assembly in Sardis write:
He who has the seven Spirits of God, and the seven stars says these things:
 

"I know your works, that you have a reputation of being alive, but you are dead.
3:2 Wake up, and keep the things that remain, which you were about to throw away, for I have not found works of yours perfected before my God.
3:3 Remember therefore how you have received and heard. Keep it, and repent. If therefore you won't watch, I will come as a thief, and you won't know what hour I will come upon you.
3:4 Nevertheless you have a few names in Sardis that did not defile their garments. They will walk with me in white, for they are worthy.
3:5 He who overcomes will be arrayed in white garments, and I will in no way blot his name out of the book of life, and I will confess his name before my Father, and before his angels.
3:6 He who has an ear, let him hear what the Spirit says to the assemblies.

3:7 "To the angel of the assembly in Philadelphia write: "He who is holy, he who is true, he who has the key of David, he who opens and no one can shut, and who shuts and no one opens, says these things:
 

3:8 "I know your works (behold, I have set before you an open door, which no one can shut), that you have a little power, and kept my word, and didn't deny my name.

3:9 Behold, I give of the synagogue of Satan, of those who say they are Jews, and they are not, but lie. Behold, I will make them to come and worship before your feet, and to know that I have loved you.
3:10 Because you kept my command to endure, I also will keep you from the hour of testing, which is to come on the whole world, to test those who dwell on the earth.
3:11 I am coming quickly! Hold firmly that which you have, so that no one takes your crown.

3:12 He who overcomes, I will make him a pillar in the temple of my God, and he will go out from there no more. I will write on him the name of my God, and the name of the city of my God, the new Jerusalem, which comes down out of heaven from my God, and my own new name.
3:13 He who has an ear, let him hear what the Spirit says to the assemblies.
 

3:14 "To the angel of the assembly in Laodicea write: "The Amen, the Faithful and True Witness, the Head of God's creation, says these things:
 

3:15 "I know your works, that you are neither cold nor hot. I wish you were cold or hot.
3:16 So, because you are lukewarm, and neither hot nor cold, I will vomit you out of my mouth.
3:17 Because you say, 'I am rich, and have gotten riches, and have need of nothing;' and don't know that you are the wretched one, miserable, poor, blind, and naked;

3:18 I counsel you to buy from me gold refined by fire, that you may become rich; and white garments, that you may clothe yourself, and that the shame of your nakedness may not be revealed; and eye salve to anoint your eyes, that you may see.
3:19 As many as I love, I reprove and chasten. Be zealous therefore, and repent.
3:20 Behold, I stand at the door and knock. If anyone hears my voice and opens the door, then I will come in to him, and will dine with him, and he with me.

3:21 He who overcomes, I will give to him to sit down with me on my throne, as I also overcame, and sat down with my Father on his throne.
3:22 He who has an ear, let him hear what the Spirit says to the assemblies."

Philadelphia
Why do you suppose he references the key of David? Notice also Isaiah 22:22
Who was trying to shut them down?
What aspect of keeping his word do you suppose Jesus was alluding to in vs 8?
vs 10 How might he keep them from the hour of testing? Xref Isaiah 57:1
What does the reward of verse 12 allude to?
What is the primary thing we are to hold fast to? Xref 1Cor 15:1,2

Laodicea
Do you suppose these people were a legitimate part of the Body of Christ at this point?
Or what do you suppose their status was?
How poorly must a Christian be living the Christian life for Jesus to make these derogatory comments?
How is humility an essential character quality to continue on in the Christian life?
What do the gold, clothes, and eye salve represent?
vs 20 If a person invites Jesus as a guest to get to know him, does that mean the person is necessarily saved as a result?
Is it appropriate for a person to base their assurance of salvation upon the fact that they prayed a prayer based upon Rev 3:20?
Notice the parallel between verse 14 and 21

vs 1-3  The word "reputation" is literally "name". They were alive in name only. There are some churches that are reckoned "alive" on the surface. They may have large numbers, or lively members. But under the surface they may be dead, nominal churches, dominated by worldly philosophies rather than the Word of God. They are "asleep", indifferent to their salvation, the negative of a greek word which is most commonly translated "watchful". I suspect he is speaking to a church dominated by nominal Christians whose spiritual discernment is dying, as the Isrealite died in the wilderness.

Justification is by faith, but not just any faith, it must be of salvific value. Our faith is measured by our deeds, as in Matthew 25 and 1John 3:10. If our deeds are found wanting, our faith is deficient for faith without works is a dead faith. But if this is the case, what is the solution? To do better deeds? No, that should not be the primary focus. For deeds are not what we put our faith in. Rather one should go back to the message of the gospel and listen carefully and obey it. For if one has saving faith in the atoning work of Christ, then one will be born of God, in which case deeds appropriate for children of God will come naturally.

vs 3 is more appropriately translated "If you are not watchful I will come as a thief". But Paul writes of those born of God:

"But ye, brethren, are not in darkness, that that day should overtake you as a thief. Ye are all the children of light, and the children of the day: we are not of the night, nor of darkness." 1Th 5:4,5

"And shall cut him asunder, and appoint him his portion with the hypocrites: there shall be weeping and gnashing of teeth." Matt 24:51

On the other hand, there is a conflict between this concept and 1Thess 5:9,10 where Paul writes "He died for us so that, whether we are awake (alert) or asleep (not watchful) , we may live together with him." And indeed most Christians are "asleep" in some area morally or doctrinally. Or is salvation limited to those who are perfect doctrinally and morally, if there exist such people? I assume that Paul was referring to "asleep" in non-essential areas. But I assume here, Jesus is referring to essential areas, as in denying his name by worshipping other Gods and consciously taking on the more overt sinful practices of the pagans so as to avoid persecution.

vs 4-6 I don't presume that "not soiling their clothes" refers to perfectly sinless behavior. But there is a sort behavior characteristic of nominal Christians which Peter describes:

"A dog returns to its vomit," and, "A sow that is washed goes back to her wallowing in the mud." 2Pet 2:22

"Whosoever is born of God doth not commit sin; for his seed remaineth in him: and he cannot sin, because he is born of God." 1John 3:9

"dressed in white", of course symbolizes purity from sin. Those who are not dressed in white have the stain of sin, for which they will be punished.

"blot out his name from the book of life". Here's a verse that calls into question the concept of eternal security. Or does it? Indeed it would if he were applying it to the nominal Christians in Sardis, but he is not. He is applying it to the true believers - those who will walk with him in white. Simply stated he means: "If you are one of those of an overcoming faith - your sins will be forgiven and your name will be written in the book of life never to be blotted out". So rather than opposing eternal security, it actually advocates it!

PHILADELPHIA

vs 7,8 The "open door" may be the same as that referred to later in vs 20 to the church at Laodicea. It could refer to an open relationship with God - which is the essential relational aspect of eternal life. It's possible to construe this as a promise of eternal security. But notice again, that he says this based on the observation of their deeds, and not simply a prayer they prayed at some point.

A similar reference to the "key of the house of David" is made in Isaiah 22:22 "I will place on his shoulder the key to the house of David; what he opens no one can shut, and what he shuts no one can open." The emphasis in Rev 3:7,8 is the fact that the Lord has opened a door which cannot be shut because He holds the key.

"little strength" is probably speaking of their external circumstances as opposed to the quality of their faith. It was in view of their faithfulness and obedience in the midst of difficult circumstances that he was impressed with.

vs 9 Once again this synagogue of Satan was mentioned in Rev 2:9 to the church at Smyrna. To have them fall down at their feet does not mean they will worship these believers, but that they will worship Jesus acknowledging that he has loved these believers - a simple act of vindication. For no doubt these Jews were slanderously accusing God of hating these Christians so as to justify their own hatred.

vs 10 One should not draw from this that whoever escapes from suffering is somehow more virtuous than those who suffer. Suffering for Christ is an honor. "For unto you it is given in the behalf of Christ, not only to believe on him, but also to suffer for his sake;" Php 1:29 Those who shy away from such suffering call into question their own salvation status.

But having suffered sufficiently to the glory of God, often God will deliver people out of difficult circumstances, even if by death. (Isaiah 57:1) Even Christ himself suffered only a few short hours in his crucifixion, whereas most crucifixions last hours longer. But what is this "hour of trial" that he refers to? Is it the time of tribulation of the seven trumpets mentioned later in Revelations? If it is, then he has certainly fulfilled his promise. For these Philadelphians are all dead now and even the church there is gone. But perhaps he may have been referring to the suffering of persecution under the sadistic Roman emperors.

vs 11 They didn't have the crown yet. He meant to hold on to what they have else they lose the potential reward of this crown. It is unclear from this passage alone whether Jesus is referring to a reward inevitable for all believers or a relative reward as in his parables in which some are rewarded with authority over 10 cities versus 5 cities. A passage that fits right in with the "hold on" idea is found in Hebrews in which the author in encouraging the believers who face persecution:

You need to persevere so that when you have done the will of God, you will receive what he has promised. For in just a very little while, "He who is coming will come and will not delay. But my righteous one will live by faith. And if he shrinks back, I will not be pleased with him." But we are not of those who shrink back and are destroyed, but of those who believe and are saved. Heb 10:36-38

For Paul even questioned himself as this matter: 1Co 9:27 "I beat my body and make it my slave so that after I have preached to others, I myself will not be disqualified for the prize."

vs 12 Xref:

Then one of the elders asked me, "These in white robes-- who are they, and where did they come from?" I answered, "Sir, you know." And he said, "These are they who have come out of the great tribulation; they have washed their robes and made them white in the blood of the Lamb. Therefore, "And one of the elders answered, saying unto me, What are these which are arrayed in white robes? and whence came they? And I said unto him, Sir, thou knowest. And he said to me, These are they which came out of great tribulation, and have washed their robes, and made them white in the blood of the Lamb. Therefore are they before the throne of God, and serve him day and night in his temple: and he that sitteth on the throne shall dwell among them. They shall hunger no more, neither thirst any more; neither shall the sun light on them, nor any heat. For the Lamb which is in the midst of the throne shall feed them, and shall lead them unto living fountains of waters: and God shall wipe away all tears from their eyes." Rev 7:13-17

"And they shall see his face; and his name shall be in their foreheads." Rev 22:4

LAODICEA

vs 14-17 This is the famous lukewarm church. Just as in Hebrews 6, nominal Christians are viewed as having had a taste of the Christian life, but haven't taken it in substantively. So also Jesus' relationship with nominal Christians is as if he has them in his mouth, but has not swallowed them into his being. They haven't been digested into part of his body. They stand precariously on the edge of salvation and their lukewarmness - their lack of decisiveness in following Christ - may result in them being ejected from association with Christ. To be lukewarm is to call yourself a Christian but live a lifestyle inconsistent with that proposition. It is to live in such a way as not to be able to distinguish you from a non-Christian.

Contentment is a virtue. But wealth can bring pride which leads to blindness to one's spiritual needs, having its focus rather on material things. One can be blind morally through the corruption of the conscience, or blind doctrinally through replacing Biblical truth with one's own opinions. To be naked is not to be clothed in the righteousness of Christ. One is reminded of the parable of the wedding feast in which a man came dressed inappropriately. He was thrown out. (Matt 22:12,13)

vs 18 I think the gold refined by faith is salvific faith which has been produced by their cooperation with God in responding correctly under trials. Peter writes of this:

1Pe 1:7 "That the trial of your faith, being much more precious than of gold that perisheth, though it be tried with fire, might be found unto praise and honour and glory at the appearing of Jesus Christ:"

The salve for the eyes is the insight which the Holy Spirit brings as one humbly submits to God's Word. It opens one's eyes both to our own condition and to the applications of scripture.

vs 19 There is often a misconception in modern Evangelicalism that rebuke is contrary to love and even sinful. Often people will misquote Jesus out of context saying "Judge not and you shall not be judged.", meaning that Christians aren't allowed to discipline one another. But of course this is contrary to Biblical Christianity as most of the New Testament affirms, as 1Cor 5,6 for example. Similarly in raising children. Letting them raise themselves or being indifferent to their sinfulness is akind to hatred.

Jesus here does not speak in terms that many would consider to be particularly "friendly". In fact I suspect that if Christians didn't know who he was, most churches would eventually treat him with a good deal of hostility and even eventually throw him out. To follow Jesus' example, Christians need to have a degree of a confrontational attitude. The objective in meeting with other Christians should not be simply to make people feel good about themselves in a nice friendly comfortable atmosphere. Christian meetings can end up being a battle ground if Jesus shows up. For he may say things that people don't want to hear and make people feel uncomfortable as I'm sure the Laodiceans felt after receiving this letter.

vs 20 This verse is often used in the presentation of the gospel, inviting unbelievers and nominal Christians to accept Christ into their lives. Jesus presents himself as on the outside trying to get in, indicating that he hasn't established an internal relationship with this person. He is also taking the initiative to do so. But the person must hear him. Notice how many times in these last two chapters Jesus says - He who has an ear, let him hear. Not everyone has prepared themselves with the spiritual perception to hear. And even those who have the understanding of what he means, not all are willing to respond properly.

To eat with someone, especially in that culture, indicated a degree of acceptance and friendship.  But inviting someone as a guest to get to know that person is much different than turning over the keys of your house to him as your Lord. You set the rules in your house, not the guest. But when you accept Jesus as Lord then he sets the rules in your house. I suspect what Jesus was referring to here was not the final act of faith whereby one is born of God, but rather an initial act of becoming a disciple of Christ and listening and learning from him. It may take a while after a person has received Christ in this manner before they come to understand the gospel and believe it with salvific faith. So don't put your faith in a once in a lifetime prayer to receive Christ. Actually believing with the right quality and right object of faith is what God requires for the atoning work of Christ to apply to us individually, and not simply going through a once in a lifetime prayer or ritual, like water baptism.

vs 21 Non-overcomers will not reign with Christ but will be condemned, as it is written:

"Blessed and holy is he that hath part in the first resurrection: on such the second death hath no power, but they shall be priests of God and of Christ, and shall reign with him a thousand years." Re 20:6
"If we suffer, we shall also reign with him: if we deny him, he also will deny us:" 2Tim 2:12