Which people made up Christianity was it Romans or Jews etc ?

In the beginning it was Jews.  After about 3-400 years, the Romans became involved.  Eventually, it became the religion of the Empire, and spread from there.

Why do you give yourself so much trouble, you, who are Atheist? huh?

Christ = Christianity!

Therefore, the washing of your heart and brain has been done by your demons, who are inside you, with this technique, you will have them with you, in hell!

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@. ---> Professor of my boots, it's me from Rome, not you, and your atheist crap, tell that to the Zoo monkeys?

If you look up the Councils of Nicaea, 325 CE where  the Roman Bishops, part of the Royal Court along with the military, invented the son of a God. Prior to that there was no Virgin Mary or three Wise Men following a star!    It was a theatrical production! 

 The motive was to unite and save an Empire in steep decline.  Rome later failed, but the Church remained.    

John 1:1-4 

In the beginning was the Word, and the Word was with God, and the Word was God. [2] The same was in the beginning with God. [3] All things were made by him; and without him was not any thing made that was made. [4] In him was life; and the life was the light of men.

You can read all about the start of Christianity from around 33 C.E. in the Bible book of Acts. It started in Jerusalem, mainly spread by Jewish converts to the resurrected Jesus Christ, but quickly included Gentiles from every nation, and they all spread it out into the world by the end of that 1st century. If you don't like the idea you have that Christianity requires 'brainwashing', tell us what source of brainwashing you suffer from.