I believe, O Lord, and I confess, that thou art, in very truth, the Christ the Son of the living God, who didst come into the world to save sinners, of whom I am chief. And I believe that this is, of a truth, thine all-pure Body, and that this is thine own precious Blood. Wherefore I beseech thee, have mercy upon me, and forgive my transgressions, whether voluntary or involuntary; whether of word or of deed; whether committed with knowledge or in ignorance. And vouchsafe that I may partake without condemnation of thine all-pure Mysteries, unto the remission of my sins, and unto life eternal.
Of thy Mystical Supper, O Son of God, accept me to-day as a communicant: for I will not speak of thy Mystery to thine enemies, neither, like Judas, will I give thee a kiss; but like the thief will I confess thee: Remember me, O Lord, in thy kingdom.
And let not this participation in thy Holy Mysteries be unto judgment upon me, or unto condemnation, O Lord, but unto the healing of soul and body.
From Isabel Florence Hapgood, Service Book of the Holy Orthodox-Catholic Apostolic Church, Houghton Mifflin, 1906, in the Liturgy of St Chrysostom, p. 105, and again in the Presanctified, p. 143. The book itself — public domain.
On the text. Hapgood prints it twice; in the Presanctified a column break splits the last paragraph around the choir's verse. The two printings agree, and are the check on each other.
Where these come from. Every prayer here is transcribed from a printed book that is out of copyright, and each one says which book and where in it. That is not fussiness. An English translation of an Orthodox prayer is a copyrighted work in its own right, separately from the Greek or Slavonic behind it, and in 2012 a monastery took a bishop to federal court for putting its translations on a website — and won. So these come from Hapgood's Service Book of 1906 and Shann's Euchology of 1891 and Book of Needs of 1894, which anyone may reprint. More on the sources and what is missing.