So the Pope is a marxist.... (wait for it)

[Occhidiangela]

Christ was a Jew. The earliest Christians were all Jews. Yet from the Council of Nicaea in 325 until the 2nd half of the 20th century, the official Catholic positions regarding Jews and the Jewish faith were hostile. For centuries the Jews were persecuted. So, what does that say about what it means to be Christian?

And the position of the Jewish establishment regarding the early Christians, Jew and Gentile alike, was ... love and kisses?

GMAFB.

It's a bit more complicated than that. The Council of Jerusalem (~50 AD) had to address whether or not Gentiles could get in on the action, could they eat pork (and shellfish, et al) and would they have to get their willies sliced. This is about 300 years before Nicea. Also some passages in Peter and James on that, as I recall. Don't have a Bible to hand at the moment.

A further point is that this sub cult or offshoot of the Hebraic faith was not a legal/recognized religion by the Romans. These are the same Romans who were military occupation of the Holy Land in the first century, the same Romans who took a recognized religion (Jewish) and put a lot of its adherents to the sword, followed up by a bit of Holy Land ethnic cleansing ... leading to the diaspora ... but it was more about politics and home rule than it was religion, as I read it.

Further your point ... it took 300 years for someone an Emperor, so a very important someone) Constantine, to formally accept that "this christian bunch" were a formal and valid religion in the empire. (Why he did that is interesting, IMO politics had a big play).

If you do a little digging, you will find that the animosity between Christians and Jews wasn't all one way. The bad blood flowed in multiple directions.

I remember something Pete said:
There is no quarrel like a family quarrel, and the Abrahamic religions are certainly a dysfynctinal family. (Not his exact words, but the sense of his bon mot).

As to the Pope (or Catholics at any rate) and Marxists, may I suggest a little research for our OP on a thing called "Liberation Theology" and where it was most common.