“So I wonder how Metzger and his ilk went back into time to modify these sources?”
They didn’t have to. The First (and Second) Century Gnostic insurgency was there to do it for them, because they hated those passages as much as you do, for exactly the same reasons, and the Gnostics were strong in Alexandria (See Valentinus), so it is not at all surprising to have Codex A be problematic in some of those passages.
The thing you seem to be missing is that there was contemporary eyewitness testimony that Codex A actually has 1 Tim 3:16 right, i.e., theos. Clarke was one of those witnesses. There were others before him who testified to the same thing. It was Hort who apparently talked the UBS folks into buying the reverse theory that you are espousing, despite evidence to the contrary. Why the caretakers of a supernatural book trusted a man who was openly skeptical of supernaturalism, I’ll never know.
Peace,
SR
You have no business attributing motives or reasons to me or attempting to put me in the Gnostic camp.
You have yet to comment on why a version like the Vulgate would not use “theos” here. Or why the manuscripts that followed Aleph didn't use “theos” at 1 Tim. 3:16.
Keeping the trinitarian definition of God in mind placing “God” instead of “he” in this passage is impossible to make sense of. How could the Father be “justified in spirit” or the Holy Spirit?
Did Hort convince the translators of the ASV (1901) to use “he” instead of “God” in this verse or were they all Gnostics too? And what led Jerome to use which instead of God in his translation? He wasn't a Gnostic was he?
Clarke was without question a fine scholar but not the only one.
The Scriptures tell us that we must have not just knowledge but accurate knowledge so it behooves to seek out that accurate knowledge.