I would suspect that the "image of God" must be something that applies to every single human being from conception till death.
My view on it is that the "image of God" is a status rather than any applied attributes.
No one asked him to join Israel, or live in Israel, or abide by their laws.
Argument from silence.
He simply chose YHWH as the God he would serve and went back home with some bags of dirt.
No, that's not what happened and you have yet to provide a verse stating all he did was choose
and, more importantly, you haven't considered what God was doing in Naaman and his life to bring about the change.
If you think a complete silence in scripture means it happened, [that’s quite a stretch].
I think everyone, including you, should refrain from speculating and making assumptions where scripture is silent and I know arguments from silence (scripture does NOT say X, therefore X must be true) are fallacious arguments to be avoided by exegetical and rational Christians.
That is what you have done.
I am not the subject of this discussion. You can either prove Naaman made a choice that saved him from sin and wrath without God effecting that choice, or you cannot. This all started because of my statement about the inherent covenant context of salvation. You are arguing someone got saved outside of such a covenant.
That does not happen.
All salvation occurs within a Christological covenant, a covenant between God and Christ, into which He brings everyone He saves. You say, no, that is not the case..... a person chooses to be saved. But you cannot provide a single verse stating such a choice was made. You infer it from what is NOT said. That is sloppy exegesis.
Now, can you provide proof Naaman made a choice outside God's covenant and that choice is what saved him, or not?