Today's gospel reading, dearly beloved, as it reaches our ears and strikes on the hearing of our minds, calls upon us to understand a great mystery. And with God's help we shall the more easily achieve this if we turn our attention to what is related shortly before. Jesus Christ, the saviour of the human race, before he instituted that faith which brings back sinners to righteousness and the dead to life, surrounded his disciples with prophetic instruction and with mighty works, so that they should believe that one and the same Christ was both the only-begotten of God, and son of man. For one of these without the other is of no profit for salvation. It is equally perilous, whether we believe that our Lord Jesus Christ is God and not man, or man and not God. “We must confess both, for just as true humanity is united in him to divinity, so is true divinity united to humanity.