I don't know about God but Hitler's was the only army in that war fighting with the blessing of the pope. Stalin was an opportunist who put the narrow national interests of Russians ahead of the interests of the working class, and in many ways backed himself into a corner with Hitler. That said, his alliance with Nazi Germany came only after the UK and other Western powers refused the alliance he sought with them, putting the Soviet Union in a position where getting control of a buffer zone in Poland and neutralizing the immediate threat of German invasion was a matter of survival.
The U.S. was indeed glad to see the USSR and Germany mutually exhaust each other, which is why the U.S. doled out aid with an eyedropper ... just enough (given the heroic sacrifices of the Soviet soldiers, workers, and farmers) to keep the Germans too occupied to shift their forces to the Western front, overwhelm the British, and leave a rival imperialist power in control of Europe. That the Soviet Union needed American aid in the first place is a testament to the degradation Stalin's counterrevolution brought to a country that a generation prior had defeated the combined strength of the U.S., UK, France, Japan, Italy, and 9 other countries while simultaneously rebuilding a shattered economy from scratch while under complete embargo by the entire rest of the world.
Say what you will about the exploitation, ethnic cleansing, and administrative/quasi-imperialist thuggery displayed by the Soviet Union in Eastern Europe; in many ways it bears favorable comparison with the U.S.'s record in Latin America, the Middle East, Southeast Asia, etc., and at any rate Stalin deserves credit for (however unwillingly) bringing the tangible benefits of socialism to tens of millions.