In our previous post, we finished establishing that each Person of the Trinity is uncreated, infinite, and eternal. Lines 11-12, meanwhile, clarify that this does not mean there are three uncreated, infinite, and eternal beings.

Lesson from the Creed

And yet there are not three eternal beings; there is but one eternal being. So too there are not three uncreated or immeasurable beings; there is but one uncreated and immeasurable being.

Athanasian Creed, lines 11-12

Explanation from Scripture

A being who is uncreated, infinite, and eternal would be God. The Father, Son, and Holy Spirit all share these divine attributes, but they are not three Gods, but one God in three Persons.

So for instance, in Revelation, the Son says: I am Alpha and Omega, the beginning and the ending … which is, and which was, and which is to come (Revelation 1:8; 22:13 KJV‬‬). He is uncreated, infinite, and eternal, but is not another God; rather, He is one Person of the Godhead, along with the Father and the Spirit.

So it is also with God the Father, with whom is no variableness, neither shadow of turning (James‬ ‭1‬:‭17‬ ‭KJV‬‬). He is unchanging and unchangeable precisely because He is uncreated, infinite, and eternal. Created beings change, but an eternal being is uncreated. Likewise, because He is infinite, He does not change; because He could only change for better or worse, becoming more or less. But infinity is neither lesser nor greater. And again, the Holy Spirit is called the eternal Spirit (Hebrews 9:14); and since eternal, He is also uncreated and infinite.

The three participate in one divine substance. They are each thus God in themselves, but are not three Gods, nor are they three parts of God.

Rather, we read: The Lord our God, the Lord is one! (Deuteronomy‬ ‭6‬:‭4‬ ‭NKJV‬‬). Again, remember that in marriage a man shall leave his father and mother and be joined to his wife, and they shall become one flesh (Genesis‬ ‭2‬:‭24‬ ‭NKJV‬‬). And likewise: the two shall become one flesh (Ephesians‬ ‭5‬:‭31‬ ‭NKJV‬‬). The man and his wife are both fully human in themselves; and in marriage, the two are one. In a similar fashion, the Father, the Son, and the Holy Spirit are each one perfectly God. There is not some Godness which the Father has, but the Son and Spirit lack, or have in a lesser degree. They are one Godhead, of the same divine substance.