[Telepathic Intruder]

"How do we explain, then, that the first followers of Christ were mostly Jews?"

Because Jesus himself was a Jew, of course. A traditional, orthodox one in every sense except that he claimed to be the Messiah and the Son of God. And he said "Salvation is of the Jews". Not that salvation is given by them, but first available to them. They were first given the Word, and were intended to spread it to the rest of the world, not hide it as though only members of an exclusive club had privilege.

[Jamestown1630]

Plenty of Christians did spread the Gospel - it took over much of the world!

But perhaps many Jews knew - and still recognize - that what they know through their own original and ancient teachings is equal and sufficient, or even superior, for THEM.

Maybe all Jesus was doing in the first place was uncovering for them the depths of what they already possessed; and they felt or feel no need to change formally - under which perspective they may find efforts to convince them to change offensive.

(If Jews want to know about Jesus, they will come to Him of their own accord. Trying to browbeat Jews in threads like this seems no different to me than all the Catholic v. whatever-Protestant-flavor threads that we see on FR - big waste of time, productive of nothing but bad blood between people.)