Since a tree [in the Garden of Eden] had brought about the downfall of humankind, it was upon a tree [the cross] that humankind crossed over to the realm of life. We give glory to you, Lord, who raised up your cross to span the jaws of death like a bridge by which souls might pass from the region of the dead to the land of the living.

—Ephrem of Edessa, Sermon on our Lord

The Apostle John writes ” If we love one another God dwells in us and his love is brought to perfection in us.” Begin to love; you will be perfected. Have you begun to love? God has begun to dwell in you. As John continues “In this we know that we abide in him and he in us, because he has given us his Spirit.” How do we know that “he has given us of his Spirit”? Ask your heart; if it is filled with love, you have received the Spirit of God.

—Augustine, Commentary on the Epistle of John, 8.12

Jesus did not overcome the insuperable obstacle presented by the divinity and enter the human sphere simply to be our saviour. Had that been all, his work would have remained unfinished, his mission of love unfulfilled. He broke through the wall surrounding the invisible, and came down into the visible world to bear witness to ‘the things that are above,’ to reveal to us ‘the secrets of his Father’s house’, to give us in concrete form what he called eternal life. What exactly is it, this famous ‘eternal life’? He himself defined it in the Gospel: ‘And eternal life is this: to know you, the only true God, and Jesus Christ whom you have sent’ (jn 17:3). So eternal life is, first and foremost, knowledge. It is a matter of knowing the Father, knowing Jesus. But it is not a question of any external, historical, analogical knowledge which we could more or less imagine, possess perhaps, even now; it is rather a question of real, supernatural knowledge which, although it is still surrounded here by the darkness of faith, is already the same as the knowledge we will have when the veil is torn aside and we see God face to face. It is a question of knowing God as he is, not as he may appear to us or as we may imagine him. This is the heart of the mystery I have tried to describe as the beyond, and which is the key to the secret of intimacy with God and the substance of contemplative prayer. In giving us ‘eternal life’ Jesus gives us that knowledge of the Father which is already our first experience of living, here on earth, the divine life; which is a vital participation, here and now, in the family of God; and which means that while we remain sons of man, we are at the same time sons of God. Jesus is the Image of the Father, the centre of the universe and of history. Jesus is our salvation, the radiance of the God we cannot see, the unquenchable fire of love, the one for whom the angels sigh, the Holy one of God, the true adorer, the eternal High Priest, the Lord of the Ages, the glory of God. Jesus is also our brother, and as such he takes his place beside us, to teach us the path we must follow to reach the invisible. And to make sure that we understand, he translates into visible terms the invisible things he has seenas man he acts as God would act; he introduces the ways of the family of God on to the earth and into the family of man.

—Carlo Carretto, In Search of the Beyond