"It is not the healthy who need a doctor, but the sick. I have not come to call the righteous, but sinners to repentance."Luke 5:31,31
To repent of sin is a condition for entry into the kingdom, as is also repenting of other such things that one had rejected about God.
Peter preached, "Therefore let all Israel be assured of this: God has made this Jesus, whom you crucified, both Lord and Christ." When the people heard this, they were cut to the heart and said to Peter and the other apostles, "Brothers, what shall we do?" Peter replied, "Repent and be baptized, every one of you, in the name of Jesus Christ for the forgiveness of your sins." Acts 2:36-38
He was calling them not only to repent of their sins in general, but more specifically to repent of their former rejection of Jesus Christ as Lord and Christ. Accepting the King is a condition for entering the kingdom. But that also incorporates accepting everything the King says - such as what constitutes sin - what constitutes an acceptable behavior in his kingdom.
John the Baptist preached repentance saying, "Produce fruit in keeping with repentance." Matt 3:8 While repentance is the intention to change, the fruit of repentance are the actions and actual changed behavior. In describing his preaching, the apostle Paul said, "First to those in Damascus, then to those in Jerusalem and in all Judea, and to the Gentiles also, I preached that they should repent and turn to God and prove their repentance by their deeds."Ac 26:20
(concerning repentance) What should we do then?" the crowd asked. John answered, "The man with two tunics should share with him who has none, and the one who has food should do the same." Tax collectors also came to be baptized. "Teacher," they asked, "what should we do?" "Donít collect any more than you are required to," he told them. Then some soldiers asked him, "And what should we do?" He replied, "Donít extort money and donít accuse people falselyó be content with your pay."
And concerning that extensive list of sins in 1Cor 6:9,10, it is written of the Christians in verse 11, "And that is what some of you were." They no longer behaved that way because they repented.
Therefore to become God's friend you may very well have to make changes in your attitudes and in your lifestyle. You may have to change your ideas about things, and about God in particular.
When giving a comprehensive presentation of the gospel and dealing with the subject of repentance, besides telling people to repent and turn to God, what else should we demand of such people concerning their repentance?