Might as well post the full version, which adds context:

God, grant me the serenity to accept the things I cannot change the courage to change the things I can and the wisdom to know the difference.

Living one day at a time, enjoying one moment at a time.

Accepting hardships as the pathway to peace.

Taking, as he did, the sinful world as it is, not as I would have it.

Trusting that he will make all things right if I surrender to His will; that I may be reasonably happy in this life, and supremely happy with Him forever.

—Reinhold Niebuhr, 1892-1971

As much as the serenity prayer comes across as some tacky shit you'd find painted on a wall in that one handwriting font in a beach house in Florida... it's the greatest distillation of human wisdom I've ever found.

I've been in therapy many years, and you wouldn't believe how often it comes up and we discuss it in the context of some problem in my life. So much of life's difficulties hinge on the axis of trying to figure out where we can place our agency and where we should.