Well whether you believe it or not, He's not just God when you believe in Him. He helps you all the time, with or without your faith. One thing does happen when you believe in Him though, He completely changes your heart, so that you will find it hard to do wroung, and easy to love and be good.
Perhaps if I gave you a little of my history it would help:
Ex-con, ex-drugdealer, ex-metalhead. I used to think believers were nuts, especially when they did things like fasting. When I landed in prison, I read the whole bible exept for psalms. I needed a bible of my own, and asked the chaplain (Pastor on the unit) for a bible. He said they didn't have any. I got down that night and said to God "if this is something you want for me, please send me a bible. The next day, another inmate came by (without my asking) with about 4-5 bibles and handed me one of them. God answered me. Since then I have had hepititis c healed, seen other people healed, heard the voice of the Lord, and have seen many miracles.
If I was only hearing a voice that did not exist, then the voice could not do miracles, or answer my prayer. It would not love me, and take care of me.
I know this is hard to believe, but let me ask you this:
How many people out there claim that Jesus did something for them? How many people out there believe in Jesus?
There is either a really big confusion, or maybe He really does exist.
I assure you, I am quite sound. Schizphrenics don't even make sense when they talk. Their sentences are usually broken, and confused, and most of the time they cannot function.