It might be said that John Calvin was something of a theologian born out of time. When you read him, particularly the French version of his Institutes of the Christian Religion, what you will find is someone who sounds more like a Patristic theologian more than one who worked in and post late medieval theology. His Christocentric emphasis, I think, leads him to sound like maybe an Athanasius or Irenaeus; he offers insights about the eternal life of salvation that operate from the catholicity borne out by ecumenical councils like the niceno-constantinopolitano-chalcedony offered towards the orthodox grammar and thought of the Church since.
More materially, Calvin’s thinking sounds almost exactly like Irenaeus’s idea of theosis, and how it took God become human in Christ for humanity to become sons of God, by the adoption of grace, and thus participants in the eternal triune life of God. Note Irenaeus, and then Calvin following:
But again, those who assert that He was simply a mere man, begotten by Joseph, remaining in the bondage of the old disobedience, are in a state of death having been not as yet joined to the Word of God the Father, nor receiving liberty through the Son, as He does Himself declare: If the Son shall make you free, you shall be free indeed. John 8:36 But, being ignorant of Him who from the Virgin is Emmanuel, they are deprived of His gift, which is eternal life; Romans 6:23 and not receiving the incorruptible Word, they remain in mortal flesh, and are debtors to death, not obtaining the antidote of life. To whom the Word says, mentioning His own gift of grace: I said, You are all the sons of the Highest, and gods; but you shall die like men. He speaks undoubtedly these words to those who have not received the gift of adoption, but who despise the incarnation of the pure generation of the Word of God, defraud human nature of promotion into God, and prove themselves ungrateful to the Word of God, who became flesh for them. For it was for this end that the Word of God was made man, and He who was the Son of God became the Son of man, that man, having been taken into the Word, and receiving the adoption, might become the son of God. For by no other means could we have attained to incorruptibility and immortality, unless we had been united to incorruptibility and immortality. But how could we be joined to incorruptibility and immortality, unless, first, incorruptibility and immortality had become that which we also are, so that the corruptible might be swallowed up by incorruptibility, and the mortal by immortality, that we might receive the adoption of sons?
What we have said will be clearer if we consider that the office of Mediator is not a common thing — that is; to restore us to God’s grace in such a way that we are made His children, we who were the children of people; to make us heirs of the heavenly kingdom, we who were heirs of hell. Who could have done that unless the Son of God had been made Son of man and had taken our condition so as to transfer to us what was His properly by nature, making it ours by grace? So we have confidence that we are God’s children, having the guarantee that the natural Son of God took a body from our body, flesh from our flesh, bone from our bone, to be united with us. What was properly ours, He accepted in his person in order that what was properly His might belong to us, and thus He had in common with us that He was Son of God and Son of man. For this reason we hope that the heavenly inheritance is ours, because the unique Son of God who completely deserves it, has adopted us as His brothers. Now if we are His brothers, we are His co-heirs.
In context, both Irenaeus and Calvin are writing against people who are attempting to denigrate the full divinity of the Son. Both thinkers identify the necessity of full divinity in Christ in order for ultimate salvation and eternal life to obtain. Interestingly, particularly with reference to Calvin, what we see is an inkling toward what we freely call theosis or divinization in the Patristic writers like Irenaeus. What is significant to me, in this regard, is that Calvin has an ontological understanding of salvation operative in and underwriting his thinking on salvation; contra the steep forensic or declarative understanding of salvation we end up seeing the scholastic Reformed or Post Reformed orthodox theologians of the Protestant period in the 16th and 17th centuries develop. This continues to be an underappreciated reality in Calvin, particularly by those who would like to read him into the Post Reformed orthodox period.
Thomas Torrance picks up on this theosis motif in Calvin’s thinking and rightly brings Calvin into the ontological frame when developing his own constructive doctrine of salvation. Again, this is rebuffed by people like Richard Muller et al. who want to read Calvin away from divinization salvific grammar, and instead see him fitting into the juridical models developed in the Post Reformation period. I think Torrance is right to align Calvin more with the Patristic Fathers rather than with the Post Reformed orthodox Fathers. I commend the aforementioned from Calvin as evidence in that direction. I also present it to you as further evidence that Calvin was someone born out of time; that he often sounds more like the Patristics than the Protestants, so to speak.
 Irenaeus, Against Heresies: Book III, Chpt. 19 [Emphasis mine].
 John Calvin, Institutes of the Christian Religion: 1541 French Edition, trans. by Elsie Anne McKee (Grand Rapids, Michigan: William B. Eerdmans Publishing Company, 2009), 223-24 [Emphasis mine].