It is interesting that long before we knew what it meant to be a "soul-winner," God blessed those who brought others to Christ. He spoke of the wisdom of taking God's message of redemption to others. There is so much imagery in this proverb that it is difficult to take it all in unless you step back and see each picture.
The first picture we see is that of the "tree of life." The fruit of the righteous one is a tree of life. What is amazing here is that the tree of life is seen very early in Scripture. The tree of life is in the garden of Eden - but is overshadowed by the tree of the knowledge of good and evil because of the first couple's sin. The tree of life is seen again at the end of Scripture in heaven where its leaves provide healing for the nations. I believe that the tree of life is a type of Christ. The only place the righteous can become righteous is in partaking of that tree - partaking of the righteousness of Christ. So, it should not be shocking to learn that the fruit of the righteous is the very life of Christ. It is that tree that brings life.
When the righteous partakes of the life of Christ consistently - they will seek to give that life to others. That is why we read the second half of this verse and do not find it at all odd that the wise man wins souls. This was why Jesus, the original tree of life , came to earth in the first place - to seek and to save that which was lost. When His life is moving through a man or woman - they will seek to win souls. Consider Jesus' first call to His disciples, "Follow Me, and I will make you fishers of men."
Wisdom is doing all that we can as we live our lives to see men and women come to Christ. Wisdom is so partaking of Christ, the tree of life, that our fruit is apparent. When we do not grasp this - when we do not realize that God's ultimate act was to give His Son for the sin of mankind - we miss that it is wisdom's greatest passion to see the love of God passed on to those who desperately need it. Truly, saints, if we are wise - if we have the fruit of Christ Himself flowing from our lives - we will take the gospel to those who are dead in sin. When we do, we will watch once again our Lord be the Tree of life - and bring the very life of God to those whose soul's we win!