One response I received with regards to my commentary on the Parable of the Sower was from a church leader who said, "What if I stay in the pulpit for 50 years and only see one or two saved souls in my ministry? Is that not MUCH fruit." There appears to be a misconception in the Christian community as to what constitutes fruitfulness. Fruitfulness is not  measured by merely counting the number of souls one allegedly saved. Notice the parable itself. It was not the sower who is being evaluated. It is the soil which is being evaluated. And "Land that drinks in the rain often falling on it and that produces a crop useful to those for whom it is farmed receives the blessing of God. But land that produces thorns and thistles is worthless and is in danger of being cursed. In the end it will be burned." Heb 6:7,8
While having an impact on others is one aspect of fruitfulness, the Bible teaches us that fruitfulness is largely measured by one's own attitude and behavior. For example it is written that "the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness and self-control." Gal 5:22,23 Or how about Eph 5:8-11 "You were once darkness, but now you are light in the Lord. Live as children of light (for the fruit of the light consists in all goodness, righteousness and truth) and find out what pleases the Lord. Have nothing to do with the fruitless deeds of darkness, but rather expose them." Nothing in these verses to indicate fruitfulness is measure by number of souls saved. In fact one wonders whether there is such a misconception in the Evangelical community in order to avoid considering issues of one's own attitudes and behaviors. Be that as it may there are plenty of verses backing up the idea that one's attitude and behavior are the measure of the Christian.
Consider the whole letter of Jude. It speaks of "certain men whose condemnation was written about long ago have secretly slipped in among you. They are godless men, who change the grace of our God into a license for immorality and deny Jesus Christ our only Sovereign and Lord." and goes through a whole list of attitudes and behaviors characteristic of such men, and also says, "These men are blemishes at your love feasts, eating with you without the slightest qualm— shepherds who feed only themselves. They are clouds without rain, blown along by the wind; autumn trees, without fruit and uprooted— twice dead." Jude 1:12 It's not referring to counting number of souls saved, but rather it's referring to their character as in "These men are grumblers and faultfinders; they follow their own evil desires; they boast about themselves and flatter others for their own advantage."
Likewise Paul warned the Corinthians, "Do you not know that the wicked will not inherit the kingdom of God? Do not be deceived: Neither the sexually immoral nor idolaters nor adulterers nor male prostitutes nor homosexual offenders nor thieves nor the greedy nor drunkards nor slanderers nor swindlers will inherit the kingdom of God." 1Cor 6:9,10 and consequently he instructs them, "Examine yourselves to see whether you are in the faith; test yourselves. Do you not realize that Christ Jesus is in you— unless, of course, you fail the test?" 2Cor 13:5 And what is the examination? It's not simply counting the numbers of souls you saved. John writes, "This is how we know we are in him: Whoever claims to live in him must walk as Jesus did." 1John 2:5,6 And "This is how we know who the children of God are and who the children of the devil are: Anyone who does not do what is right is not a child of God; nor is anyone who does not love his brother." 1John 3:10
Therefore Peter says, "make every effort to add to your faith goodness; and to goodness, knowledge; and to knowledge, self-control; and to self-control, perseverance; and to perseverance, godliness; and to godliness, brotherly kindness; and to brotherly kindness, love. For if you possess these qualities in increasing measure, they will keep you from being ineffective and unproductive in your knowledge of our Lord Jesus Christ. But if anyone does not have them, he is nearsighted and blind, and has forgotten that he has been cleansed from his past sins. Therefore, my brothers, be all the more eager to make your calling and election sure. For if you do these things, you will never fall, and you will receive a rich welcome into the eternal kingdom of our Lord and Savior Jesus Christ." 2Peter 1:5-11
"So I say, live by the Spirit, and you will not gratify the desires of the sinful nature. For the sinful nature desires what is contrary to the Spirit, and the Spirit what is contrary to the sinful nature. They are in conflict with each other, so that you do not do what you want. But if you are led by the Spirit, you are not under law. The acts of the sinful nature are obvious: sexual immorality, impurity and debauchery; idolatry and witchcraft; hatred, discord, jealousy, fits of rage, selfish ambition, dissensions, factions and envy; drunkenness, orgies, and the like. I warn you, as I did before, that those who live like this will not inherit the kingdom of God. But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness and self-control. Against such things there is no law. Those who belong to Christ Jesus have crucified the sinful nature with its passions and desires. Since we live by the Spirit, let us keep in step with the Spirit." Gal 5:16-25

But now as for fruitfulness in ministry - namely fruitfulness as an impact on others, that's largely between God and the one being ministered to. Paul says, "I planted the seed, Apollos watered it, but God made it grow. So neither he who plants nor he who waters is anything, but only God, who makes things grow." 1Cor 3:6,7 And this doesn't even include reaping. There are alot of aspects of Christian minsitry. To have such a narrow view that only reaping is a measure of person fruitfulness is distorted. To overinflate the value of reaping over that  sowing and watering just leads to Christians focussing on that one narrow ministry as constituting the whole of Christian ministry. Jesus said, "I sent you to reap what you have not worked for. Others have done the hard work, and you have reaped the benefits of their labor." John 4:38 And this is troubling because "reapers" may often take credit for other people's hard work, taking more credit than is their due, which is why God killed Ananias and Sapphira. Reaping is easy work. And what is easy deserves less reward. Isn't that fair? In fact just prior to that verse Jesus said, "Even now the reaper draws his wages, even now he harvests the crop for eternal life, so that the sower and the reaper may be glad together. Thus the saying ‘One sows and another reaps’ is true."
But it is neither the sower who produces the fruit, neither is it the one who waters it who produces the fruit, and certainly the reaper can't take credit for the fruit. For he only comes along after the fruit is produce. Rather the soil produces the fruit in cooperation with God. Notice that it says, "But the seed on good soil stands for those with a noble and good heart, who hear the word, retain it, and by persevering produce a crop." Luke 8:15 Whose noble and good heart is it referring to? The sowers? No. The one who waters? No. The reaper? No. It's referring to the soil.
Yes statistically speaking if one does as the sower in the parable throwing seed around, as it says in 2Cor 9:6, "Whoever sows sparingly will also reap sparingly, and whoever sows generously will also reap generously." But the effect of sowing is not a measure of one's personal fruitfulness, but rather the fact of sowing. The effect is not only a matter of the degree one sows, but also the state of the soil. So it's not only a poor measure of personal fruitfulness, it's also a poor measure of comparing one Christian to another.
Worse yet are institutional church leaders who measure their personal fruitfulness by popularity or attendance. Again as with all matters, just stick with what the Bible says. For popular ideas in Christianity are often at odds with the Bible.

The Berean Christian Bible Study Resources