The idea of winning souls is Scriptural. Solomon wrote, “The fruit of the righteous is a tree of life; and he that winneth souls is wise” (Proverbs 11:30). Of course, that inspired statement should be considered in its context. In the minds of many evangelical and fundamentalist Christians today soul-winning is merely an attempt to teach lost people a few facts and then lead them in making a decision, usually settled by their repetition of some form of “the sinner’s prayer.” The context of Proverbs 11:30 includes the truth that Solomon, a wise man, was teaching a wise way of life. He was presenting a path to walk; a path of thinking, living, speaking, working, loving, investing, spending, etc. in a wise manner. He was teaching a lifestyle of wisdom. Solomon did not teach a method whereby a person could merely repeat some words in a prayer, declaring themselves, from that point on, to be a wise person. He actually taught repentance from foolishness and simplicity, to the life of the wise, and laid out what that would look like in actual practice.
So, “he that winneth souls is wise” should be understood to mean that a wise person turns foolish and simple people to the path of wisdom to truly live in a wise way. That has nothing to do with a practice of just getting people to pray a prayer stating that they will be wise. Now, this is not to imply that there would be no decision or prayer involved when a foolish or simple person turned to wisdom. Certainly there would. But, if they spent the rest of their lives declaring that they made such a decision, while keeping on in foolishness and simplicity, then it would be folly to conclude that they truly did decide to pursue wisdom. After all, Proverbs 20:11 states the self-evident truth that “even a child is known by his doings, whether his work be pure, and whether it be right.” Even the character of a child is known, not by what he claims to be, but by what he does. How much more is this true of men and women?