Theosis ("deification," "divinization") is the process of a worshiper becoming free of
hamartía("missing the mark"), being united with God, beginning in this life and later consummated in bodily
resurrection. For Orthodox Christians, Théōsis (see 2 Pet. 1:4) is salvation. Théōsis assumes that humans from the beginning are made to share in the Life or Nature of the all-
Holy Trinity. Therefore, an infant or an adult worshiper is saved from the state of unholiness (
hamartía — which is not to be confused with
hamártēma “sin”) for participation in the Life (
zōé, not simply
bíos) of the Trinity — which is everlasting.
This is not to be confused with the heretical (apothéōsis) - "
Deification in God’s Essence", which is imparticipable.
Theosis - OrthodoxWiki
2 Peter 1:4
His divine power has given us everything we need for life and godliness through our knowledge of him who called us by his own glory and goodness. Through these he has given us his very great and precious promises, so that through them you may
participate in the divine nature and escape the corruption in the world caused by evil desires.
(NIV)
The phrase “participate in the divine nature” (NIV) or “partakers of the divine nature” (KJV, OSB) is a translation of: “γένησθε θείας κοινωνοὶ φύσεως.” [
Greek NT] The Greek for “participate” or “share” is κοινωνος (koinonos) which has a range of meanings. It has been used with reference to sharing in glory (1 Peter 5:1), sharing in Christ’s suffering (Philippians 3:10), and fellowship in the Holy Spirit (Philippians 2:1). It can have a spiritual/sacramental sense. Participation in a religious service, Christian or otherwise, has definite spiritual consequences. Participation in a pagan sacrifice results in participation with demonic forces (1 Corinthians 10:20) and likewise participation in the Eucharist results in participation in Christ’s body and blood (1 Corinthians 10:16). The emphasis here is on participation, transformation, and experiential change, rather than a judicial declaration of legal status. This distinction is central to the different attitude Orthodox and the Reformed have toward the fullness of salvation in Christ.
Theosis and Our Salvation in Christ - Orthodox Reformed Bridge
This is totally different from what Mormons teach; that's for sure!