“Here (John 16:7-11) the Holy Spirit’s ministry is threefold: he convicts the unbeliever of his own sin, of God’s righteousness, and of his condemnation before God. The unbeliever so convicted can therefore be said to know such truths as “God exists,” “I am guilty before God,” and so forth.
This is the way it has to be. For if it weren’t for the work of the Holy Spirit, no one would ever become a Christian. According to Paul, natural man left to himself does not even seek God: “None is righteous, no, not one; no one understands, no one seeks for God” (Rom 3:10–11 esv). Unregenerate man cannot understand spiritual things: “The unspiritual man does not receive the gifts of the Spirit of God, for they are folly to him, and he is not able to understand them because they are spiritually discerned” (1 Cor. 2:14 rsv). And he is hostile to God: “For the mind that is set on the flesh is hostile to God; for it does not submit to God’s law; indeed, it cannot” (Rom. 8:7 esv). As Jesus said, men love darkness rather than light. Left to himself, natural man would never come to God.
The fact that we do find people who are seeking God and are ready to believe in Christ is evidence that the Holy Spirit has already been at work, convicting them and drawing them to him. As Jesus said, “No one can come to me unless the Father who sent me draws him” ( John 6:44 esv).
Therefore, when a person refuses to come to Christ, it is never just because of lack of evidence or because of intellectual difficulties: at root, he refuses to come because he willingly ignores and rejects the drawing of God’s Spirit on his heart. No one in the final analysis really fails to become a Christian because of lack of arguments; he fails to become a Christian because he loves darkness rather than light and wants nothing to do with God”
Craig, William Lane., and William Lane. Craig. Reasonable Faith: Christian Truth and Apologetics. Wheaton, IL: Crossway, 1994. 46-47.