What does that mean when we say we are “in Jesus Christ,” when we pray “through Jesus Christ,” when we say we are “the body of Christ?” Here’s Blessed Isaac of Stella from today’s Office of Readings:
“What Jesus, the Son of God, is by generation, his members are by adoption, according to the text: As children you have received the Spirit of adoption, enabling you to cry, Abba, Father.
“Through his Spirit, Jesus gave us the power to become children of God, so that all those he has chosen might be taught by the firstborn among many brothers and sisters to say: Our Father, who are in heaven. Again he says elsewhere: I ascend to my Father and to your Father.
“By the Spirit, from the womb of the Virgin, was born our head, the Son of Man; and by the same Spirit, in the waters of baptism, we are reborn as his body and as children of God. And just as he was born without any sin, so we are reborn in the forgiveness of all our sins. As on the cross he bore the sum total of the whole body’s sins in his own physical body, so he gave his members the grace of rebirth in order that no sin might be imputed to his mystical body. It is written: Blessed is the one to whom the Lord imputes no guilt for sin.
“The ‘blessed one’ of this text is undoubtedly Christ. Insofar as God is his head, Christ forgives sins. Insofar as the head of the body is one, there is no sin to forgive; and insofar as the body that belongs to this head consists of many members, there is sin indeed, but it is forgiven and no guilt is imputed.
“ In himself he is just: it is he who justifies himself. He alone is both Saviour and saved. In his own body on the cross he bore what he had washed from his body by the waters of baptism. Bringing salvation through wood and through water, he is the Lamb of God who takes away the sins of the world which he took upon himself. Himself a priest, he offers himself as sacrifice to God, and he himself is God. Thus, through his own self, the Son is reconciled to himself as God, as well as to the Father and to the Holy Spirit.”