Why don't atheists, agnostics and others believe in God?
One of the biggest reason the disbelievers give is the evil in the creation, “the problem of evil.” If God is all powerful and all good, why did he allow evil in his creation? Mark Twain was disillusioned with Christianity and religion because he only saw the paradoxes and the hell-fire damnation of religiosity. So he wrote the following in a book not published until after his death:
"A God who could make good children as easily as bad, yet preferred to make bad ones; who could have made every one of them happy, yet never made a single happy one; who made them prize their bitter life, yet stingily cut it short; who gave his angels eternal happiness unearned, yet required his other children to earn it; who gave his angels painless lives, yet cursed his other children with biting miseries and maladies of mind and body; who mouths justice and invented hell - mouths mercy and invented hell - mouths Golden Rules, and forgiveness multiplied by seventy times seven, and invented hell." [Mark Twain, The Mysterious Stranger, Chap. 11]
This perception of the inexplicable paradoxes and negativity found in religion was superseded by Christ's teaching on Love. Unfortunately, Jesus' teaching was taken over by those who didn't understand and they changed Christ's teachings of forgiveness and love into the teachings of hell and damnation.
Yet despite Christ’s teachings, one can see the paradoxes in the Bible pointed out by Mark Twain. And if we are honest with ourselves we will question the traditional teachings on God.
In my book on God, God: God is the Becoming-One, which is also called the God Papers, I point out the paradoxes pertaining to God and his essence: the paradoxes of good and evil in the creation. The full answer I give in my book. To put it in a few words, there is a reason for evil and it has to do with the ability to perceive good and appreciate good. Good and evil are comparative qualities. You need both to know either. You need to compare both with each other to know either. Without a period of evil, you would not even know what good is, you would not appreciate it. If God at first gave us a peaceful and good environment without the experience of evil, we would not even recognize the value of good because we would have nothing to compare it to. Read the God Papers and the New Mind Papers to better understand this. The suffering may not be worth it now, but we will thank our Creator later.