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.
"Reasonable Faith: Christian Truth and Apologetics". Book by William Lane Craig, 1994.