John 6:38

“I didn’t come to do my own will; I came to do my Father’s will.” The Father and the Son have a oneness in the sense of unity; they were at one—united in purpose to do what happened through Jesus’ ministry, including Gethsemane through Golgotha: “Not my will but yours be done” (Luke 22:42; Mark 14:36; Matthew 26:39, 42).

Taking these representations of his body and blood says to the Father that we too qualify our will by his. As Christ accepted his cross to show his obedience to the Father and his love for us, so we observe these emblems of the cross to express our love to the Father and Son for agreeing together to do this for us.