No one is perfect, nothing is perfect, not even the universe itself.
If God exists and is all-knowing and benevolent, there should be no reason to pray.
Because I don't believe! :)
The existence of any sort of God is an entirely man-made construct almost as old as humankind itself, and had I been born thousands of years ago there would be people there telling me to believe in Thor, Zeus or Poseidon - but I don't see anyone strapping C-4 to themselves to appease Osiris or Wotan.