“By his own powers man cannot see God, yet God will be seen by men because He wills it. He will be seen by those He chooses, at the time He chooses, and in the way He chooses, for God can do all things. He was seen of old through the Spirit in prophecy; He is seen through the Son by our adoption as his children, and He will be seen in the kingdom of heaven in His own being as the Father. The Spirit prepares man to receive the Son of God, the Son leads him to the Father, and the Father, freeing him from change and decay, bestows the eternal life that comes to everyone from seeing God.

“As those who see light are in the light sharing its brilliance, so those who see God are in God sharing His glory, and that glory gives them life. To see God is to share in life.”

Saint Irenaeus. Adversus Haereses or Against Heresies. Quoted in Office of Readings for Wednesday of the Third Week in Advent, (vol. 1, p. 288) and cited there as: Lib 4, 20, 4-5: SC 100, 634-640.

Note: Seeing God isn’t usually physical seeing, just as knowing God isn’t intellectual knowing. But understand that God was seen, is seen, and will be seen.

Saint Irenaeus also makes an interesting flip by saying that the former was through the Spirit, the middle in the Son, and the latter in the Father. (I think we usually say of old through the creating Father, then in the incarnate Jesus, and ultimately in the Holy Spirit’s leading the Church. So I suppose we’re the ones making the flip.)