After the ascension of Jesus, the Gospel was spread to "Gentiles". As the teachings (so remote from anything anyone outside Israel had encountered before) spread into the Grecian influenced Roman empire, the teachings became "hellenized". This also would have been indirectly caused by a lack of knowledge, since copies of the "Old testament" would not be available, and upon hearing of about a "new God", people could have converted, but only knowing their former ways of worship, continued in those ways but to a new diety.
Under Constantine, scattered groups of "Christians" (Christ coming from a Greek word. He would not have been called this by his disciples,since he was Jewish) ceased being persecuted and instead became the "state religion". To reduce protests by previously none-Christians, he officially "Christianized" well documented ancient pagan holidays such as the Winter Solstice (Christmas), and the Spring Equinox (Easter).The day of worship was set as Sunday to appease the large group of Apollo worshippers.
Nothing about Christianity in its form of worhip reflects anything from Bible. It does however reflect the many religions in the Roman empire in the early centuries, as well as pagan customs from much earlier.
I also read a very interesting book a couple of years ago outlining a arguement that Constantine was actually a follower of Mithras, and that there are many parallels in Christianity to Mithraism, and that the reason it went from the height of it's popularity in the 3rd century to disappearing by the 4th century was due to its direct assimilation.
