Stay aware of the enemy's tactic of sidetracking with "rabbit trails." Occasionally people have a genuine difficulty with "Darwin's theory," "hypocrites in the Church," etc., but in most cases they are nothing but "hedges." Sinners tend to make hedges, behind which they try to hide from God, as did Adam. The best way to get a sinner out from behind a hedge is to beat it with the rod of the Law, so that he stands exposed before his Creator. Get him to admit that he has lied, stolen, and looked with lust. If he says, "I don't believe in Judgment Day," just gently say, "That doesn't matter, you will still have to face God on Judgment Day, and you've admitted that you are a lying, thieving, adulterer at heart. God gave you a conscience so that you would know right from wrong. You will have no excuse." There goes another minute. Gone forever. Go share your faith while you still have time.