In Romans, Paul says that Israel is under judgment, not because of some general failure to live up to the demands of an impossibly perfect law, but because they stumbled over the Messiah, the holy stumbling stone (Rom 9:32-33).
This insight is not new to Paul. Indeed, Jesus Himself identifies Himself as the occasion for Israel’s fall (cf Rom 11:11-12), as well. “If I had not done among them the works that no one else did, they would not be guilty of sin, but now they have seen and hated both Me and My Father” (John 15:24). It is their rejection of Christ which is their decisive sin, which is why Jesus goes on to say that the Spirit’s role will be to convict “the world” (kosmos) concerning sin, righteousness and judgment (John 16:8).
And this role in convicting “the world” of sin, does not, as it turns out, revolve around some sort of Puritanesque “pounding the law home in order to drive the sinner to Christ.” Rather, Jesus says, the Spirit bears witness “concerning sin, because they do not believe in Me” (John 16:9). Their great sin is unbelief (cf Heb 3:19).
And likewise, “concerning righteousness, because I go to My Father” (John 16:10); i.e. having been vindicated by My resurrection, I will ascend to rule at His right hand as His Messiah.
None of this, of course, is to pretend that first century Jews were remarkably holy and perfect until Christ came along. But in terms of the law, given to guide them under the old creation, many of them could indeed say that they were “blameless” (as Paul says regarding himself in Philippians 3, and as Luke says regarding Zechariah and Elizabeth in 1:6 of his Gospel).
Read the rest! = Jesus and Paul on the Fall of the Blameless.