Prior to the 4th Century, the Nezarim and the Ebionim (as early Christians were known then) were not really too different from ethnic. The big split happened by the 4th century where Hebraism became Judaism and the Jewish Sect who followed the teachings of Yeshua (Hebrew for Jesus) became officially a Eastern Roman State religion. The difference grew greater once Greco-Roman elements were introduced by means of doctrinization and the universality of G-d became prevalent among the gentiles.
Doctrine in the early Christian church helped unify the people by helping them to understand the differences between Judaism and the new form of Christianity - Roman Catholic.
Please be more specific in your question. There were many early church fathers and Christian martyrs.
The Patriarchs were found at the top of the early Christian church hierarchy.
Christian Church
Go to church
they farted
The Writings of the Church Fathers.
Two examples would be baptism and what Christians call "the Lord's Supper" or communion. Both were a part of Judaism, though with other names, before Christ came.
Saturnalia
it was the same but they didn't know as much as we do
Stephanie Robin Jernigan has written: 'Origins of the Early Christian architecture of the Iberian Peninsula' -- subject(s): Architecture, Early Christian, Church architecture, Early Christian Architecture
They defended and explained Christian beliefs.