You have free will. Under oppressive conditions, and under great duress, you may suffer some kind of emotional collapse and blame God for all your misery. Under such conditions you may try to pay God back by no longer claiming to be a Christian.
In those circumstances God is understanding and merciful. But why, oh why, with free will would you turn against a God you *know* loves you and is guilty of no sin?
You wouldn't, is the simple answer. Once you die and are free of your oppression, you will agree that God was never wrong, and that you were wrong to abandon Him. In fact, it was a staged act, to pay God back for what you perceived was something He was to blame for.
How do I know this? I have been through these ups and downs myself. When terrible things happen to you, it seems you have no recourse but God. And if He won't help you in the immediate term, then it does seem that He is responsible. You have nobody to point the finger at, for your continuing misery, but God Himself.
Of course, in our more sane moments, we know that God loves us, cares about us, but will not give up His lordship. We must submit to Him!