In the situation Western man finds himself, we can supply no demonstration of the necessity for prayer or even of its usefulness. It is futile to pretend that prayer is indispensable to man. Today he gets along very well without it.
Jacques Ellul1

You have not because you ask not.
James 4:2

God answers our prayers, and he does not seem to begrudge doing so. He displays good will and cheer—at times, an almost puckish sense of humor.

Consider Genesis 18 where Abraham learns God is going to destroy the cities of Sodom and Gomorrah. Abraham is horror stricken and pleads on behalf of Sodom: "Will you sweep away the righteous with the wicked? What if there are fifty righteous people in the city?"

The Lord answers, "If I find fifty righteous people in the city of Sodom, I will spare the whole place for their sake."

Abraham decides fifty might be a touch high: "What if the number is five less than fifty? Will you destroy the whole city because of five people?"

"If I find forty-five there, I will not ...