God the Father of Heaven, have mercy on us. God the Son, Redeemer of the world, have mercy on us. God, the Holy Spirit, have mercy on us. Holy Trinity, One God, have mercy on us. O Living Bread ...

"Christians are baptized in the name of the Father and of the Son and of the Holy Spirit: not in their names, [Cf. Profession of faith of Pope Vigilius I (552): DS 415.] for there is only one God ...

We believe in One Lord, Jesus Christ, the only Son of God … of one Being with the Father … [who] was made man … he suffered death and … he rose again. … We believe in the Holy Spirit ...