single-letter difference between God and the IRS
Said letter is "R" --- God tells us to "PRAY with faith and without ceasing", whereas the IRS tells us to "PAY with faith and without ceasing". Otherwise, both "mighty entities" are essentially the same... they act like they've got your best interests at heart, but in reality they just mercilessly "milk you for all you're worth" and then turn their backs on you when you've been drained dry... no further explanation necessary.
Come to think of it, the single-letter difference between God and the IRS isn't the only direct correlation between the two "superpowers" --- because the IRS tells us to PAY so much, it causes poorer folks to PRAY to God a lot more due to their worries over becoming even more destitute from shelling out for their income taxes!