Being completely dead to sin is not theosis?
I looked at+John Chrysotsom's homilies X, XI (thanks D-fendr).
But let's look at what the Apostle actually says; at the relevant verses:
v.6 knowing this, that our old self was crucified with Him, in order that our body of sin might be done away with, so that we would no longer be slaves to sin; [comment: here he reiterates that those who accepted Christ are dead to sin, free from sin through dying into Christ].
v.7 for he who has died is freed from sin. [comment; doesn't get much clearer that this; we are dead to sin and therefore free form sin]
v.10 For the death that He died, He died to sin once for all; but the life that He lives, He lives to God. [comment: this is unrelated to dying to sin, but it is one of those sentences where one must wonder if +Paul considers Christ equal to Father in divinity]
v.11 Even so consider yourselves to be dead to sin, but alive to God in Christ Jesus. [comment: again, he states that we are dead to sin; we are free form sin; what else can that mean except that we can sin no more?!]
v.12 Therefore do not let sin reign in your mortal body so that you obey its lusts, [commnet: here he speaks as if just a few verse above he didn't say that we are free from sin]
v.18 and having been freed from sin, you became slaves of righteousness. [comment: again, having been freed...now we can only do righteous deeds]
All in all, I think the protestants are reading these lines as basically saying: when you become a Christian you become dead to sin, free from sin and sin no more. That would be theosis (except that theosis requires a life-long dying unto oneself).
Most protestant denominations I'm familiar with would deny believers never sin after they've received eternal life and initial saving faith in Christ. Rather, while they remain in fellowship with God, they are dead to sin or separated from the penalty of sin. We become free from the bondage of sin because we have already the first hope satisfied in us, namely eternal life. Our next hope is in our remaining in fellowship with Him, putting on the mind of Christ, recognizing there are rewards for us in heaven based upon our good works performed through faith in Him when we perform according to His will and Plan. We also recognize we stumble repetitively in sin after salvation prior to the first death, but by calling upon His promises of 1stJohn 1:9 we still have life through faith in Him. Even though we are slaves to righteousness, we might still sin from the influence of the old man, disobey in our volition, but we nevertheless remain His and slaves to Him forever.
I'm somewhat familiar with the doctrine of kenosis, as it pertains to Christ in hypostatic union, but not as fluent in the language of theosis. Does it touch upon the indwelling of different persons of the Godhead in Catholic doctrines?