Through Holy Communion, the man of faith becomes one body with Christ, one compound, one mixture. This happens not in some theoretical sense, but actually and existentially. Christ in His love for us ‘was not content only to become man, to endure buffeting and be killed, but even mingled Himself with us. He changes us into His own Body, not in faith only, but in reality.’

“The Divine Liturgy – A Commentary in the Light of the Fathers” by Hieromonk Gregorios
Quotations from St. John Chrystostom