Factors contributing to the diversity of early Christian groups

Far flung groups and the difficulty of communication;stories may develop differently as they spread to new regions

The lack of an agreed upon canon of authentic writings

Communities were dependent upon what stories they had access to, what stories told by leaders, and what communications with other groups were possible

Different cultural groups present from the beginning, causing different understandings of Jesus: especially Jews and non-Jews

The Christian movement spread very quickly and not in an organized way

Jesus was relatively unknown so there would not have been good documentation about his ideas

New, mysterious, and radical ideas are open to a variety of interpretations

Many of the sayings attributed to Jesus are ambiguous and can be interpreted in differnt ways

Followers of Jesus had different expectations of what he would do, and interpreted what happened afterward differently as well

The change in expectations after his death (lack of appearance of the end time) caused many  to reevaluate what Jesus and the movement stood for

Unless you follow Matthew, the other gospels don't depict Jesus choosing an heir with whom he communicated his core beliefs

Each founding community had their own traditions and did not communicate much with other groups

An apparent "quest for religiosity" in the Roman Empire took many forms

It's not like Judaism or the pagan religions of the time were uniform in their ideas either

Much debate over what kind of Jew Jesus actually was

Strong leaders like Paul or Marcion can be very persuasive

The cataclysms of the Jewish war and the Roman response to Christianity made calm reflection difficult

The destruction of the Temple caused a massive re-evaluation of Judaism, so that made new forms more possible

Everyone saw in Jesus what they needed to see