The one who ate my food has raised his heel against me. From now on I am telling you before it happens, so that when it happens you may believe that I AM. Amen, amen, I say to you, whoever receives the one I send receives me, and whoever receives me receives the one who sent me. John 13:18-20
Jesus knew of the betrayal beforehand, he mentions it, so they will know that what he says about who he claims is truth. That he is "I AM," and in that context he is one with God. He gives us something else to think about too, whoever receives the one he sends receives him. He will be sending us his very self in the Eucharist. His presence in the Eucharist is tangible, he is one with our Father, in the Bread of Life.
He gives us also his apostles, who have brought him to us through the years. They receive him by the very hands of the Bishops. We receive from these men passed down to us a gift of God's love, his very self. When they minister and consecrate the host they bring forth Jesus' all encompassing presence. That is why the call of the Priesthood is very special. A belief that they act in God's stead has to be present in each one, that they bring forth the spirit of our Lord in consecration. If there is no belief that this is so, then we do not receive him as he says in today's Gospel. How would it be possible to have our Lord when the hands that consecrate do not receive him in faith also.
He is who he is, Jesus is I AM, he reigns supreme within our hearts when we receive him from the one's he sent.