Mental effort leads from one thing to another and reinforces the original idea. We may not know now, but we do not have to accept pre-conceived beliefs. How do atheists "know" that there is no God? How do religions know that there is a God? We need arguments that stand to reason.
If there is an all-knowing power we call God, does He occupy Himself with our daily problems? We only need to consider the natural disasters to arrive at an answer. We even call disasters "acts of God" but this is folklore. If they were God's acts then we would have to accept his existence as hostile to us. Then what reason would He have to be hostile?
We can argue that He does not exist because he does not answer our prayers, but this argument is suspect because we have a vested interest. Why should he answer our prayers? His existence may not be linked with his stewardship for us.
For arguments in favour of his existence, we can look to our experience. The regularity, the symmetry of all things around us suggest that the spaceship earth is properly adjusted, and travelling on auto-control. Who set up the controls? All this suggests that some sentient, super intelligence was involved. The existence of a God or intelligence much higher than ours has some merit.
We also have a power to think, one that exceeds our physical capabilities. Using our minds, we can travel in time, and we can shrink the space around us. The power of our mind can heal certain diseases. Our imagination seems to have no bounds.
This suggests another possibility, that the super intelligence exists within us. That God is embedded in our minds. That we have inside us a shared power of the spiritual to which we can turn for help. When we pray, we draw our strength from within. The power of our mind, our will, may make things happen. God exists in our minds because we want Him to be there. Is this a figment of our imagination? Maybe, but that imagination is another Dimension, one in which our physical bodies do not belong, one where God does belong. Is God real? Here we need to consider reality. Maybe we live in so many different worlds!