Why do you say that only God can change a person's heart? I'm a freshman in college studying psychology, and it seems to me that psychologists can do a lot of good to help people—maybe as much as religion does.
Yes, psychologists and psychiatrists can help us understand ourselves, and give us insight into the reasons we do the things we do. Some people have been deeply scarred by their past, for example, and a gifted and spiritually-sensitive counselor can be very helpful to them.
But what is our basic problem? The Bible says we each have a basic, hard-core spiritual problem that we can never solve on our own–and that problem is sin. Don’t think of sin as simply doing things that are wrong; sin in the Bible is like a crippling virus, or a toxic chemical in a river. It manifests itself in selfishness and rebellion against God, and no matter how hard we try, we still put ourselves first.
This is one reason why we need God, for only He can give us a new heart, and replace our self-centeredness with His love. God’s promise is true: “I will give you a new heart and put a new spirit in you; I will remove from you your heart of stone” (Ezekiel 36:26).
This has been the experience of millions of Christians throughout the ages–and it can be your experience as well. Don’t blindly go the way of the crowd, but by faith turn to Christ and ask Him to take over your life. He will–and your life will never be the same.