This is the prayer that was read to the nation on radio by Franklin D. Roosevelt as Allied troops were invading Nazi-occupied Europe on D-Day, June 6, 1944.

“Almighty God, our sons, pride of our nation, this day have set upon a mighty endeavor, a struggle to preserve our Republic, our religion, and our civilization, and to set free a suffering humanity. Lead them straight and true; give them strength to their arms, stoutness to their hearts, steadfastness in their faith.
They will need Thy blessings. Their road will be long and hard. For the enemy is strong. He may hurl back our forces. Success may not come with rushing speed, but we shall return again and again; and we know that by Thy grace, and by the righteousness of our cause, our sons will triumph.
… For these men are lately drawn from the ways of peace. They fight not for the lust of conquest. They fight to end conquest. They fight to liberate. They fight to let Justice arise—among all thy people. They yearn but for the end of the battle, for their return to the haven of home. Some, will never return. Embrace these, Father, and receive them, Thy heroic servants, into Thy kingdom.
And for us at home— fathers, mothers, children, wives, sisters and brothers of brave men overseas, whose thoughts and prayers are ever with them– help us, Almighty God, to rededicate ourselves in renewed faith in Thee in this hour of great sacrifice…. And let our hearts be stout, to wait out the long travail, to bear sorrows that may come, to impart courage unto our sons wheresoever they may be.
… With Thy blessing, we shall prevail over the unholy forces of our enemy. Help us to conquer the apostles of greed and racial arrogance. Lead us to the saving of our country, and with our sister nations into a world unity that will spell a sure peace– a peace invulnerable to the schemings of unworthy men. And a peace that will let all men live in freedom, reaping the just rewards of their honest toil.
Thy will be done, almighty God. Amen”