Knowledge of God becomes eternal life. Clearly “knowledge” here means something more than mere factual knowledge, as, for example, when we know that a famous person has died or a discovery was made. Knowing, in the language of sacred Scripture, is an interior becoming one with the other. Knowing God, knowing Christ, always means loving him, becoming, in a sense, one with him by virtue of that knowledge and love. Our life becomes authentic and true life, and thus eternal life, when we know the One who is the source of all being and all life. And so Jesus’ words become a summons: let us become friends of Jesus, let us try to know him all the more! Let us live in dialogue with him! Let us learn from him how to live aright, let us be his witnesses! Then we become people who love and then we act aright. Then we are truly alive.

[Pope Benedict, homily at the Lord's Supper 1 April 2010]