Use Psychology In Christian Witnessing
I have learned by experience that if you want to win a debate, and attempt to change the other person's beliefs. Do not tell your opponent that he is wrong, or a fool, etc. Do not attack with insults. Attack with facts and knowledge. As soon as you put a person down your opponent gets mad and refuses to listen to you. You have turned him off. Logic does not defeat feelings.
Of course to change a person's mind he must be a person who has been fooled into believing false information, and you must present evidence to counter his false beliefs. But if he is an agent of Satan, no amount of kindness or facts will change his mind, he already knows you are right. But don't assume everyone is an agent of Satan, or you will be tempted to get angry and say something that will turn them off.
Sometimes you can learn from the enemy when he uses a winning strategy. How did Satan convinced Adam and Eve that God was not telling the truth? He asked a question that made them think for themselves. "Yea, hath God said?" Did he really mean you were not to eat of the tree? Actually if you eat of the tree you will be like Him and have all knowledge.
Whenever an enemy uses a weapon, it can be taken away from him and used against him.