12 Shall then the wicked man see God too? Of whom Isaiah says, “Let the ungodly be taken away, that he see not the Glory of God.” Both the ungodly and the godly then shall see that Form; and when the sentence, “Let the ungodly be taken away that he see not the Glory of God,” shall have been pronounced; it remains that as to the godly and the good, that be fulfilled which the Lord Himself promised, when He was here in the flesh, and seen not by the good only, but by the evil also.
He spoke among the good and evil, and was seen of all, as God, hidden, as Man, manifested; as God ruling men, as Man appearing among men: He spoke, I say, among them, and said, “Whoso loves Me, keeps My commandments; and he that loves Me, shall be loved of My Father, and I will love him.” And as if it were said to Him, And what will You give him? And “I will,” He says, “manifest Myself to him.” When did He say this? When He was seen by men. When did He say this? When He was seen even by them, by whom He was not loved.
How then was He to manifest Himself to them that loved Him, save in Such a Form, as they who loved Him then saw not? Therefore, seeing that the Form of God was being reserved, the Form of man manifested; by the Form of man, speaking to men, conspicuous and visible, He manifested Himself to all, both good and bad, He reserved Himself for them that loved Him.
Source: Sermons on Selected Lessons of the New Testament (New Advent)