What a good word. It means “to make divine”, or “to deify”. I’ve learned that it’s at the center of the Roman Catholic and Orthodox understandings of justification. The belief is that what Jesus accomplished on the cross opened the way for us to be made like Him, more specifically in our obedience to God. Oddly, this strikes me as a fuller salvation than the simple legal transaction that we Protestants take justification to be. (We had an debt we couldn’t pay. Jesus paid the price for us. We get off scot-free without any necessary life change.)
It’s often thought to be a type of salvation-through-works, which strikes me as a complete misunderstanding. The belief, actually, is that we are enabled to live rightly because of our contact with a sanctifying, renewing, life-giving God. Jesus’ death on the cross opened the way for us to come into the presence of God, and to be changed by Him—not to be removed from His presence every time we sin, as before the death of Christ. Thus, every good work is completely of grace; grace enables us to live like God. I find that to be a beautiful and awe-inspiring belief.
Now, I’m still wrestling with and evaluating this view of justification, but I must admit that it strikes me (initially, at least) as more beautiful, more far-reaching and more biblically coherent than the Protestant view. (That itself is kind of frightening.)