I know this may come as a surprise to some people but Jesus was a Jew not a Christian. He lived like a first-century Jew. His followers were Jews also and they lived like first-century Jews. His bible was the Tanakh (TNK) what we call the Old Testament. Since his first disciples were all Jews and the Jerusalem church was built around Jewish beliefs. They met and taught in the Temple and synagogues and we know they incorporated the Psalms into their worship. (Acts 3-6) Should we not assume the original church was Jewish and they took aspects of the Jewish synagogue and incorporated them into their practices.
The Church Hymns were the Psalms originally (Acts 4) and we see songs about Jesus coming on to the scene a little later. All the would have been sung/chanted like a Psalm in the synagogue. There was no need to change since they were all the same.
The early Jerusalem company were faithful in attendance at the temple and in obedience to the Jewish law but in addition they had their own special services among themselves with prayer mutual exhortation and breaking of bread daily in private houses. This breaking of bread served a twofold purpose It was a bond of fellowship and a means of support for the needy. The expectation of the speedy coming of the Lord made the company at Jerusalem a waiting congregation in which the support of the less well to do was provided by the gifts of the better able so that they had all things common. The act was much more than that however It was a continuation and a reminder of the Lord’s Last Supper with His disciples before His crucifixion It had therefore from the first a sacramental significance Williston Walker – A History of the Christian Church (Free Download)
So what does this mean to us?
While everything around us changes some things do remain close to the same. However different, the remnants are there. Wee see the use of the Psalms every week in Orthodox Churches along with the Chanting and reading of the daily scripture. The taking of the Eucharist in Higher churches which is the culmination of the Divine Liturgy was the taking of the evening meal or “breaking of bread” in the Jewish tradition.
While even the Orthodox Church has changed over the centuries if we look hard enough we can see traces of the original Jewish Church.