The serenity prayer by Reinhold Niebuhr, never fails to calm my soul whenever I face spiritual and psychological turbulence:
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,
living one day at a time;
enjoying one moment at a time;
taking this world as it is and 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.
Amen.