I believe, O Lord and I confess that Thou art truly the Christ, the Son of the living God, Who came into the world to save sinners, of whom I am chief. Moreover, I believe that this is truly Thy most pure Body and this is truly Thine Own precious Blood; wherefore I pray thee: Have mercy on me and forgive me my transgressions, voluntary and involuntary, whether in word or deed, in knowledge or in ignorance. And vouchsafe me to partake without condemnation of Thy most pure Mysteries, unto the remission of sins and life everlasting. Amen.
When Coming to Partake of Holy Communion say these verses of Symeon Metaphrastes:
Behold, I approach the Divine Communion.
O Creator, let me not be burnt by communicating:
For Thou art Fire, consuming the unworthy.
But, rather, purify me of all impurity.
Then again say:
Of Thy Mystical Supper, O Son of God, receive me today as a communicant; for I will not speak of the Mystery to Thine enemies; nor will I give Thee a kiss, as did Judas, but like the thief do I confess Thee: Remember me, O Lord, in Thy kingdom.
Furthermore, these lines:
Be awe-stricken, O mortal, beholding the deifying Blood;
For It is a fire that consumeth the unworthy.
The Divine Body both deifieth and nourisheth me.
It deifieth the spirit, and wondrously nourisheth the mind.