Let me try to pin you down on this.
Is this verse not a reference to an event in history, the giving of the law of Israel?;
indeed, that they were entrusted with the oracles of God;
Yes or no answer please. Don't drown us with other texts, just answer the question, please.
Is this verse not a reference to Israel's history not living up to their covenantal obligations after the giving of the law?
What then? If some did not believe, their unbelief will not nullify the faithfulness of God, will it?
Yes or no answer please. Don't drown us with other texts, just answer the question, please
Finally, there is this:
But now apart from the Law the righteousness of God has been revealed,
Is this not a reference to the present - the entry of Jesus into the picture?
Yes or no answer please. Don't drown us with other texts, just answer the question, please.
It is clear that Romans 3 is, among other things, a re-telling of the history of Israel from the giving of the Law till the present moment.
And where does Romans 3:20 appear? It appears before the "but now". And the use of the "but" in "but now" is clearly a way of saying that things have changed.
No one would say "The Law gives knowledge of sin, but now apart from the Law.......and not expect to be understood as saying that things have changed with respect to the law.
You never squarely addressed the essence of this line of reasoning. You have bombarded us with all sorts of material that may well be correct, but which artfully evades the argument about the progression of time in Romans 3 and the "but now" that clearly puts 3:20 in the rear view mirror.