It might surprise you to learn that I agree with part of what you say: No one should be forced to believe in God. We each stand alone before God, and we each must make our own personal commitment to Him.
I also know as well as you do that throughout history tyrants and madmen have used differences over religion as an excuse for hatred and war. But does that mean God approved of what they were doing (and still do)? No, not at all. When Peter attacked one of Jesus' opponents, Jesus rebuked him and warned, "All who draw the sword will die by the sword" (Matthew 26:52). Jesus' way is the way of love, not hate.
I can't help but feel, however, that you don't reject God just because of what some people have done in the name of religion. I suspect your real problem is deeper than that: You want to run your own life, and you don't want anyone else–including God–to tell you how to live. But is that wise?
Instead, I urge you to look at Christ as He is found in the Bible. When you do, you will realize that God not only exists, but that He loves you and has a plan for your life. Look at Christ with an open heart and mind. Don't let anything come between you and Christ because He alone is "the way and the truth and the life" (John 14:6).