Abstract
In this paper I deal with the beginnings of the history shared by Christianity and Judaism and their mutual relationships. By the help of the analysis of extant early Christian sources and Jewish sources from the same era I seek not just to describe the actual development, but also the intentions and incentives which caused it.
I'm concerned with the Christian self-understanding as new Israel and the christological interpretation of Old Testament, which are in the centre of church delimitation against the synagogue. Together with the inclusion of pagans into the church and thus impeachment of the God's election of Jews there are also questions against which the Judaism demarcates itself in relation to the church - even before AD 70.
I'm showing that the synagogue was in need of delimitation against church similarly as church against synagogue. That is why I disagree with usual blaming of just one side for the division.
With a critical outlook on both sides I'm coming to the conclusion that the historical development was so to say necessary and inevitable for the mutual self-identification.