[Forest Keeper]

It still doesn't answer: why did Jesus need to be sanctified?

I don't think the Bible indicates there was a "need". Jesus said Himself:

John 17:19 For them I sanctify myself, that they too may be truly sanctified.

That explains why. Christ consecrated Himself to the Father and as a consequence that holiness spread to the elect through the Spirit. See also:

1 Cor. 1:30 : It is because of him that you are in Christ Jesus, who has become for us wisdom from God—that is, our righteousness, holiness and redemption.

God says to his people "be holy because I am holy." He doesn't say "I make myself holy so that you may be holy."

He says both, but in different contexts. The first just describes the result without explaining the "how". The second explains what makes us able to be holy. It is not a command of something we can do of ourselves, but rather an encouragement of having the right mindset in experiencing God working through you.

Only someone who is not sanctified can become sanctified.

That is only if the concept of sanctification is a one time event. The Bible says it isn't. Believers become more and more sanctified as they mature in the faith.

[Kolokotronis]

Kosta: “Only someone who is not sanctified can become sanctified.”

FK: “That is only if the concept of sanctification is a one time event. The Bible says it isn’t. Believers become more and more sanctified as they mature in the faith.”

If “sanctification” is the western equivalent of theosis, then certainly it is a process, at least for the overwhelming majority of us. Or is sanctification not theosis?