All blame to Paul for keeping the division alive since then through his policy of Replacement Theology.
Paul's replacement theology? OK, let's talk about it.
Paul said, "For if the firstfruit is holy, the lump is also holy and if the root is holy, so are the branches. And if some of the branches were broken off and you, being a wild olive tree, were grafted in among them and with them became a partaker of the root and fatness of the olive tree..." (Romans 11:16-17)
Why were the natural branches broken off?
Paul explained, "You will say then, 'Branches were broken off that I might be grafted in.' Well said, because of unbelief they were broken off, and you stand by faith. Do not be haughty, but fear."
(Romans 11:19-20)
The branches were broken off because of unbelief. However, "And they also, if they do not continue in unbelief, will be grafted in, for God is able to graft them in again." (Romans 11:23)
How long will you remain in unbelief?