Not only that, but many of them, despite calling themselves Christians, believe that God has a separate covenant for modern Jews that doesn't require them to profess faith in Jesus Christ to be saved.

I remember hearing just a whisper of that when I was pretty young and being like "huh?". The fate of unrepentant jewish souls didn't particularly interest me, so I didn't follow it any further. I tried to tell my jewish friends that they should convert to Christianity, but it didn't go very well.