For the Son is the Word, and therefore we are not to understand that anything in Him is cognisable by the senses. He is wisdom, and in wisdom there can be no suspicion of anything corporeal. He is the true light, which enlightens every man that comes into this world; but He has nothing in common with the light of this sun. Our Saviour, therefore, is the image of the invisible God, inasmuch as compared with the Father Himself He is the truth: and as compared with us, to whom He reveals the Father, He is the image by which we come to the knowledge of the Father, whom no one knows save the Son, and he to whom the Son is pleased to reveal Him. And the method of revealing Him is through the understanding. For He by whom the Son Himself is understood, understands, as a consequence, the Father also, according to His own words: He that has seen Me, has seen the Father also. (Book I, Chapter 2, Part 6)

What does it mean to understand? When we stand under a tree, a bridge, almost any construction we can observe with some intimacy the nature of the thing. We can see its structure and how it works.

The Greek ginosko also suggests direct experience and intimacy, even sexual intimacy. But the verb ginosko also points to a knowledge (gnosis) that is considerably beyond what we observe.

Plato writes of gnosis, "This knowledge (gnosis) is not something that can be put into words like other sciences; but after long-continued intercourse between teacher and pupil, in joint pursuit of the subject, suddenly, like light flashing forth when a fire is kindled, it is born in the soul and straightway nourishes itself." (Epistle VII 341c-e)

It is a knowing that begins in relationship, in experiences with another, and through this relationship and experience a far greater knowledge is gained.

"If you know Me, you have known My Father also; from now on you know Him, and have seen Him." Philip said to Him, "Lord, show us the Father, and it is enough for us." Jesus said to him, "Have I been so long with you, and yet you have not come to know Me, Philip? He who has seen Me has seen the Father; how can you say, 'Show us the Father'?" (John 14:7-9)