14 Christ you see Man and God; He does manifest to you the Man, God He reserves for you. Now see how He reserves God for you, who does manifest Himself to you as Man. “Whoso loves Me,” says He, “keeps My commandments; whoso loves Me shall be loved of My Father, and I will love him.” And as if it were asked, “What will You give to him whom You love?” “And I will manifest Myself,” says He, “to him.” What means this, Brethren? He whom they saw already, promised that He would manifest Himself to them.
To whom? Those by whom He was seen, or those also by whom He was not seen? Thus speaking to a certain Apostle, who asked to see the Father, that it might suffice him, and said, “Show us the Father, and it suffices us” — Then He standing before this servant's eyes, in the form of a servant, reserving for his eyes when deified the Form of God, says to him, “Have I been so long time with you, and have ye not known Me? He that sees Me, sees the Father also.” Thou ask to see the Father; see Me, you see Me, and dost not see Me.
You see what for you I have assumed, you do not see What I have reserved for you. Give ear to My commandments, purify your eyes. “For whoso loves Me, keeps My commandments, and I will love him.” To him as keeping My commandments, and by My commandments made whole will I manifest Myself.
Source: Sermons on Selected Lessons of the New Testament (New Advent)