St. Gregory Palamas ca. 1296-1359
Whoever asserts that the perfect union with God is accomplished without the deifying grace of the Spirit, but is only a relative thing and accomplished by imitation, in a way similar to people who are fond of each other and grow alike in their ways; and, moreover, who says that the deifying grace of God is a condition inherent in our rational nature which becomes active merely by virtue of this moral imitation, but that it is not a supernatural and inexpressible illumination and divine activity which is seen invisibly by those made worthy of it and comprehended incomprehensibly: this person should know that he has tumbled unaware into the error of the Messalians. For, if deification be a potential inherent in nature and so included within the definition of nature, then he who is deified must necessarily be himself God by nature. Such a person should not attempt to smear those who stand fast with his own rebellion and try to blame the faith of the blameless. Instead, putting aside his own opinion, let him learn from those who are experienced or who have been taught by those with experience that the grace or divinity is not related to anything else whatever, nor does there exist any potential in nature capable of receiving it, since it would otherwise not be grace but merely the manifestation of an activity proper to our being. Deification would not be miraculous if it should occur as the result of some potential for its reception, for in that case it would clearly be a work of our nature instead of God’s gift, and the person deified would then in fact be able to become God by nature and acquire the title of “Lord”! For the natural potential of everything that exists is comprised of nothing other than the unswerving impetus of nature toward its proper activity. How in that case could deification be said to take the one deified outside of himself? If it were still take place within the bounds of nature, then this [traditional] expression would be meaningless. The grace of deification is therefore beyond nature, beyond virtue and knowledge, and, according to Saint Maximus, all these things fall infinitely short of it. While every virtue, including that imitation of God that is within our power, prepares a capacity in the recipient for divine union, it is still grace that accomplishes the unutterable union itself. It is by means of grace that all of God co-indwells with all those who are worthy, and that the whole of the saints co-inheres wholly with the whole of God. Thus they receive into themselves God entire and, as a kind of reward for their struggles in ascending to Him, they possess Him, Himself alone, Who has made them worthy of becoming His members, and He indwells them as a soul is entwined with its own body. (Tomos of Mount Athos in Defense of the Hesychasts)
