Jack Alexander researched the origin of the Serenity prayer and he believed the original Serenity Prayer was written by Reinhold Niebuhr. Others credited with the first writing are an anonymous English poet, an American naval officer and even the early Greeks.
The version used at meetings of Alcoholics Anonymous today was discovered in the obituary section of a newspaper by "Newsman Jack" in about 1942. He showed the clipping to the New York office and it was quickly printed on to cards and sent out to the fellowship.
Here is an original version:
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, this 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 in the next. Amen