The Catholic and Orthodox Liturgical Traditions were born out of liturgical Jewish Temple services. The Eucharistic ceremony, for example, was a way for the congregation to accept Christ’s sacrifice for them, and to pledge themselves to God in return.
That newly Christianized Greeks and Romans brought some of their cultural traditions and adapted them to Christianity is not evidence of apostasy. Indeed, it seems that the Apostles, particularly Paul, approved of it to some extent because he rejected a strictly Hebrew form of Christianity. The Early Christian community developed a new culture based on the fact that the Covenant spread around the world and it mixed peoples of vastly different traditions together.
Selah!