This is originally a song, but could be used as a prayer for both spiritual and real battle:
"I stand in the field, by the order of God,
I abandon my rank, for a place in heaven,
I die for freedom, I shall not give up on my faith,
That's what I dare.
The Cross is my shield, salvation is my loot,
I shall keep on marching, though I shall fall dead.
I don't waver, for in this battle,
I seek peace for my soul.
The blood that came out of wounds for my salvation,
Hardens my will, silences my needs.
As I'm a Catholic, it goes right through my heart,
That is rightous in faith.
The death of our Saviour stands as a battle cry,
So that evil deeds may perish.
Perversions of freedom, attacks on the holy faith,
Shall be abolished.
May we be not blinded by temptations of this world,
For God, let's defend the faith of His saints.
For the only payment for our work,
Is to be in heaven with God."
The Orthodox can replace the "The blood that came…" part with this:
"Our Mother is merciful, I hope she'll show up,
And bless us with Her brave hands
So that I'll have victory
As a defender of the faith."