St. Hilary continues to play with and illustrate the verb to know:
Now God shews clearly in the cases of Adam and Abraham that He does not know sinners, but does know believers. For it was said to Adam when he had sinned: ‘Adam, where art thou?’ (Gen 3:9). Not because God knew not that the man whom He still had in the garden was there still, but to shew, by his being asked where he was, that he was unworthy of God’s knowledge by the fact of having sinned. But Abraham, after being for a long time unknown—the word of God came to him when he was seventy years of age—was, upon his proving himself faithful to the Lord, admitted to intimacy with God by the following act of high condescension: ‘Now I know that thou fearest the Lord thy God, and for My sake thou hast not spared thy dearly loved son’ (Gen 22:12).
To reiterate, the verb to know that St. Hilary is quoting from 1 Corinthians 14:37-38 is ἐπιγινωσκέτω which is more accurately translated as let him recognize. Thus, when He asks Adam where He is, it is not due to the fact that He does not know where He is, but rather that He no longer recognizes Him as a righteous man. Adam, having sinned, moved away from God — thus, God frames the question in terms of location.
In contrast, God knows (recognizes) in Abraham a truly deep faith because (like Himself) He is willing to sacrifice his only-begotten son by Sarah. It would be good also to examine here the verb to fear. At its root in Hebrew is the verb to tremble with a connotation of to feel reverence or to hold in respect.
In Greek, the root of the word terror is τέρας, which means monster; however, like the Hebrew, there is a connotation of wonder. The presence of the τέρας is always accompanied by an act of power, to which one has a sense of wonder and awe.
Thus, the fear that Abraham displays by being willing to sacrifice his son is born of a deep respect and honor of God, by whom Abraham is awed and is filled with wonder. Also implied is a great deal of trust. What God asks of him makes little sense, because Isaac has been promised to be the seed through which Abraham will father the nations and yet God asks for Isaac’s life.
Abraham so trusts, so honors and so respects God that he does not stay his hand until the intervention of an angel. What God does not allow Abraham do to — sacrifice his only-begotten for the sake of the nations — God Himself does in and through His Only-Begotten Son — our Lord, God and Savior Jesus Christ. Thus, God recognizes in Abraham righteousness — a willingness to sacrifice for the salvation of the world.