Einstein gave grudging acceptance to "the necessity for a beginning" and eventually, to "the presence of a superior reasoning power," but never did he accept the doctrine of a personal God.  Two specific obstacles blocked his way.  According to his journal writings, Einstein wrestled with a deeply felt bitterness toward the clergy, toward priests in particular, and with his inability to resolve the paradox of God's omnipotence and man's responsibility for his choices. 

"If this being is omnipotent, then every occurrence, including every human action, every human thought, and every human feeling and aspiration is also His work; how is it possible to think of holding men responsible for their deeds and thoughts before such an almighty being?  In giving out punishment and rewards He would to a certain extent be passing judgment on Himself.  How can this be combined with the goodness and righteousness ascribed to Him?" 

Seeing no solution to this paradox, Einstein, like many other powerful intellects through the centuries, ruled out the existence of a personal God.