What I think you are saying is that maybe there is a God but you've seen so many cruel acts in the name of peoples "GOD" that it tends to make you dis-believe in a God.
(Whew! That was tough to get out!)
If so then we are not that far apart. I am disgusted in what people can justify in the name of their Lord, and these horrific terrorist attacks are no different. Committing suicide and cold-blooded murder in the name God is absolutely despicable.
Here's the flip-side: The Bible, the Koran, etc are filled with wonderful words of wisdom and peace (and history) if people would only follow them instead of contorting them for evil purposes.
Bible: Love thy neighbor as they self, don't steal, lie or bear false witness against others, etc.
Koran: Do you think you can enter the garden of bliss without facing the trials and tribulations of those before you?
People just need to mature a bit and learn from the mistakes of our ancestors. Either we do it now or blow ourselves up with nuclear weapons soon. Remember the Drake equation. Compassion, religious tolerance and erradication of religious radicalism are just three things that may improve the chances that we will achieve World Peace before we achieve World War 3.
Lastly, I do not have any proof that God exists. Being schooled as an engineer I never could comprehend how God could really exist until about 3-4 years ago when I discovered I could not scientifically determine that the universe created itself prior to the big bang. After that, I have no problem seeing how evolution progressed to our current stage in humanity. I also see how humanity has progressed far enough to destroy itself if things don't change course. Maybe that's why I cling to the hope that religion teaches?
Anyway, I'll not be disturbing you anymore since I sense that I may be annoying many people here.
Peace be with you.