13 When is He to manifest Himself to them that love Him? After the resurrection of the body, when “the ungodly shall be taken away that he see not the Glory of God.” For then “when He shall appear, we shall be like Him; for we shall see Him as He is.” This is life eternal. For all that we said before is nothing to that life. That we live, what is it? That we are in health, what is it? That we shall see God, is a great thing. This is life eternal; this Himself has said, “But this is life eternal, that they may know You the Only True God, and Jesus Christ whom You have sent.” This is life eternal, that they may know, see, comprehend, acquaint themselves with what they had believed, may perceive that which they were not yet able to comprehend.
Then may the mind see what “eye has not seen, nor ear heard, neither has it ascended into the heart of man;” this shall be said to them at the end, “Come, you blessed of My Father, receive the kingdom which has been prepared for you from the beginning of the world.” Those wicked ones then shall go into everlasting burning. But the righteous, whither? Into life eternal? What is life eternal? “This is life eternal, that they may know You, the Only True God, and Jesus Christ, whom You have sent.”
Source: Sermons on Selected Lessons of the New Testament (New Advent)