I know next to nothing about Christianity, but I know a few things about Judaism. And I've never encountered this idea in Judaism. Do you have a source for this? Is this actually a teaching of the Law of Moses, as you call it, or just something Christians think Jews believed?
Seems like a straw man.
> Enter New Testament: Jesus Christ of Nazareth, comes not to abolish the law, but to fulfil it, such that every man (being) receives the FREE gift of salvation, and eternal life.
Pardon my cynicism but this seems kind of ridiculous. God made a bunch of laws about how people should behave, presumably because there's right and wrong and the particular things God cares about matter, and then Jesus renegotiated the deal on behalf of everyone? So we can all do whatever we want, like rape, steal, homosexuality[0]... it's all cool. Jesus paid your debt, go sin.
[0] Intentionally grouping murder and gay sex together because the Old Testament calls these things bad behavior. If Jesus renegotiated the deal by arguing that some of these things are not really bad, so maybe some of the rules should be changed but others should be kept, I'd get that. But that's not the claim you're making.