God grant me the serenity
to accept the things I cannot change,
courage to change the things I can,
and the wisdom to know the difference.
I also like the full version of the original (c.1942) by theologist Reinhold Niebuhr:
God, give us grace to accept with serenity
the things that cannot be changed,
courage to change the things
which should be changed,
and the wisdom to distinguish
the one from the other.
Living one day at a time,
Enjoying one moment at a time,
Accepting hardship as a pathway to peace,
Taking, as Jesus did,
This sinful world as it is,
Not as I would have it,
Trusting that You will make all things right,
If I surrender to Your will,
So that I may be reasonably happy in this life,
And supremely happy with You forever in the next.