St. Patrick's Breastplate is a popular prayer attributed to one of Ireland’s most beloved patron saints. According to tradition, St. Patrick wrote it in 433 A.D. for divine protection before successfully converting the Irish King Leoghaire and his subjects from paganism to Christianity. (The term breastplate refers to a piece of armor worn in battle.)

More recent scholarship suggests its author was anonymous. In any case, this prayer certainly reflects the spirit with which St. Patrick brought our faith to Ireland! St. Patrick's Breastplate, also known as The Lorica of Saint Patrick was popular enough to inspire a hymn based on this text as well. (This prayer has also been called The Cry of the Deer.) 

I arise today 
Through a mighty strength, the invocation of the Trinity,
Through belief in the Threeness,
Through confession of the Oneness
of the Creator of creation.

I arise today
Through the strength of Christ's birth with His baptism,
Through the strength of His crucifixion with His burial,
Through the strength of His resurrection with His ascension,
Through the strength of His descent for the judgment of doom.

I arise today
Through the strength of the love of cherubim,
In the obedience of angels,
In the service of archangels,
In the hope of resurrection to meet with reward,
In the prayers of patriarchs,
In the predictions of prophets,
In the preaching of apostles,
In the faith of confessors,
In the innocence of holy virgins,
In the deeds of righteous men.

I arise today, through
The strength of heaven,
The light of the sun,
The radiance of the moon,
The splendor of fire,
The speed of lightning,
The swiftness of wind,
The depth of the sea,
The stability of the earth,
The firmness of rock.

I arise today, through
God's strength to pilot me,
God's might to uphold me,
God's wisdom to guide me,
God's eye to look before me,
God's ear to hear me,
God's word to speak for me,
God's hand to guard me,
God's shield to protect me,
God's host to save me
From snares of devils,
From temptation of vices,
From everyone who shall wish me ill,
afar and near.

I summon today
All these powers between me and those evils,
Against every cruel and merciless power
that may oppose my body and soul,
Against incantations of false prophets,
Against black laws of pagandom,
Against false laws of heretics,
Against craft of idolatry,
Against spells of witches and smiths and wizards,
Against every knowledge that corrupts man's body and soul;
Christ to shield me today
Against poison, against burning,
Against drowning, against wounding,
So that there may come to me an abundance of reward.

Christ with me,
Christ before me,
Christ behind me,
Christ in me,
Christ beneath me,
Christ above me,
Christ on my right,
Christ on my left,
Christ when I lie down,
Christ when I sit down,
Christ when I arise,
Christ in the heart of every man who thinks of me,
Christ in the mouth of everyone who speaks of me,
Christ in every eye that sees me,
Christ in every ear that hears me.

[Note that people sometimes pray a shorter version of this prayer just with these 15 lines about Christ above. The conclusion follows below.]

I arise today
Through a mighty strength, the invocation of the Trinity,
Through belief in the Threeness,
Through confession of the Oneness
of the Creator of creation.