myotherusernameisbetter
The original worshipers of the god that christians worship now were Jews, then came Christianity so what happens?
The Jews believed in God and were looking towards the coming of the Messiah.
The Christians believe in God and are looking back to the coming of the Messiah, which is what Christmas is all about (Jesus the Messiah).
Some Jews believe Jesus was the Messiah, some believe he was just a good man. A Jew that believes Jesus WAS the Messiah is technically a Christian, since the New testament says there is no difference with how you approach God, whether you're a Jew, Gentile, male or female, etc.
And then of course Muslims worship the same god but their heaven is filled with virgins (of whatever religion I am not sure).
The religion you speak of is Islam, and it's not the same God. Islam is a religion based on the bible but with a few twists. It came about around 600 years after the bible and so you can work out which was the original and who copied who!
God is quite clear: not all roads lead to Rome when it comes to gods and God. We are told to have no other gods and Jesus said "I am the way the truth and the life. No man comes to the father BUT BY ME."
So, technically the current Jews and Christians disagree, so is their heaven split as they apparently believe in the same god, but obviously, prior to christianity, jews and christians did not disagree as Christians didn't exist.
Gentiles (non-Jews) were able to follow the God of the Jews, just as non-Christians can have access to God in the modern day. Its all about choice. Don't forget, some Jews believe Jesus was the Messiah they had all been waiting for, and those Jews agree with the Christians. Remember also that the early Christians were all Jews to start with, and the only difference was the acceptance that Jesus was who he said he was: the awaited Messiah.
So does current heaven as Christians see it consist of only Christians or Christians plus Jews who existed prior to christianity or what?
Anyone who, as John 3:16 says: whosoever "believes in HIM" shall have eternal life with God. Believe in him isn't saying "is a good person" or "was baby baptised".... that would be works. And we are not saved through our works, whether Jew or Gentile. It is by GRACE you have been saved, through faith, and not of your own works. As Ephesians 2:8 says "For it is by grace you have been saved, through faith--and this is not from yourselves, it is the gift of God"
A gift for all, whether Jew or Gentile.