Here is a sampling of key Patristic quotes on Theosis:
Irenaeus of Lyons: (2nd century)
our Lord Jesus Christ, the Word of God, of His boundless love, became what we are that He might make us what He Himself is (Against Heresies Book 5, Preface)
We believe the Savior can make us as He is (e.g. Moroni 7:48)
Clement of Alexandria: (2nd century)
the Word of God became a man so that you might learn from a man how to become a god (Exhortation to the Greeks, 1)
We believe that we not mere creations, but veritable children of God, who can become as our Father is.
Origen of Alexandria: (3rd century)
It was by the offices of the first-born that they became gods, for He drew from God in generous measure that they should be made gods, and He communicated it to them according to His own bounty. The true God, then, is "The God," and those who are formed after Him are gods, images, as it were, of Him the prototype. (Commentary on John Book II, chapter 2)
We believe we are created in the image and likeness of God with the capacity to become like Him.
Athanasius of Alexandria: (4th century)
For the Son of God became man so that we might become God (On the Incarnation of the Word 54.3)
Through His atoning sacrifice Jesus Christ does not merely provide a way to get us back to how things were before the Fall, but to take us far beyond that point, to make us joint-heirs with Him (see further discussion of the relevant theology on my channel here).
Augustine of Hippo: (5th century)
But he himself that justifies also deifies, for by justifying he makes sons of God. ‘For he has given them power to become the sons of God’. If then we have been made sons of god, we have also been made gods.(On the Psalms 50.2)
This concept of deification is consistent with the teachings in
Doctrine & Covenants 132:20.
(many other relevant Biblical & Patristic citations are available here)
All of the above are consistent with what Latter-day Saints believe. Of course, Latter-day Saints also believe more about Theosis than is preserved by the Patristic writers (our belief in Theosis is based on modern revelation, not solely deduction from ancient writings)
A similar point could be made with respect to modern declarations of belief in many faiths: they tend to be much lengthier and go into far greater detail than the ancient texts that introduce the matter (e.g. virtually all commentaries on the Gospel of Matthew are longer than the Gospel of Matthew).
As a Latter-day Saint, I do not feel a need to explain away the straightforward meaning of these passages. I believe what these Patristic citations say about Theosis; I also believe a lot more on the topic. I believe God knows more on the matter than is found in the passages preserved by Irenaeus, Clement, and others, and that God has spoken through modern prophets to reveal a portion of that knowledge.
The teachings of the Church of Jesus Christ of Latter-day Saints on Theosis are based upon modern revelation, not deduced from the Patristic teachings. However, there is nothing in the Patristic citations above that is not in harmony with what Latter-day Saints believe today.
Disclaimer: these thoughts are the product of my own study and do not constitute official statements by the Church of Jesus Christ of Latter-day Saints