Q: I was having a discussion on religion with my friend. He is an atheist and believes more in Satan than God. If we have another discussion, how should I defend my position as a believer and bring him closer to God?
Your question is timely as recently there has been a debate on Nightline on the question, "Does Satan Exist?" (see above).
First, I would recommend you graciously explore why he/she believes in Satan and not God. What exactly does he believe about Satan? Who is Satan? What evidence is there for the existence of Satan, but not the existence of God? Does he believe in God at all? Why does he claim to be atheist if he believes in an entity such as the devil? Listen patiently and carefully, and try to understand where they are coming from. Sometimes, a person's disbelief in God is not purely scientific or intellectual. For example, they may refuse to believe in a God of love if they have suffered or been hurt or felt unloved. Since they do not feel love in their life, they conclude that a God of love cannot exist.
Second, I would say you must understand, from Scripture, who the devil is. It's going to be very hard to defend your position unless you know what the Bible says about the devil. For a good summary, visit CARM.org's article on the devil HERE. In short, Satan is a fallen angel who opposes God who is leading a rebellion against God. His primary motive is to elevate his throne above God. He counterfeits all that God does, hoping to gain the worship of the world. Additionally, Satan is the ultimate source behind every false cult and world religion. Satan will do anything and everything in his power to oppose God, and those who follow God. However, Satan’s destiny is sealed—an eternity in the lake of fire (Rev. 20:10). For more information, visit this site - which has links to other questions & their answers including "If God is all-powerful, why doesn't he just kill Satan?"
Third, I would challenge your friend to really examine whether believing in Satan over God makes sense. If anything, the fact that your friend observes evil and suffering in the world (i.e. Satan's influence) means he/she is judging by a objective moral standard. Without a standard (something more than our subjective opinion about what is and is not moral), we have no right to say what is and is not evil.
[Answered by Pastor HM, who had a friend in high school that believed in Satan, but not God]