Oh yes, Christianity is I think quite syncretic. Let us first accept that protestantism derives from Catholicism, as a reaction against one or more aspects of Catholic practice, then look at some practices:
In Catholic and Anglican practice, morning worship takes place facing east where the sun (Son) is rising: an adaptation from Roman worship of Apollo.
We celebrate the birth of Jesus at mid-winter (Northern Hemisphere), celebrating the birth of the sun (Son) - again Apollo. We even have continued the mid-winter feast with turkey and mistletoe and candle-lighting in mid-summer down under.
As missionaries transported Christianity to other parts of the world, so the religion was regionally adapted to fit existing relgions (cf Mexico and the Dia de los muertos, or the cargo cults of the South Pacific)
I have long been interested in world religions and find they have so much in common at base. One onoly needs to read the Sufi mystics, the Upanishads and the Christian mystics to see how much they have in common at this deep level of experience. The differences that I see tend to be culturally based. The differences between, for example, Islam and Christianity seem not greater than, say, the differences between the Fundamentalist Right of the USA and the Unity movement.
The bottom line for me is that I can learn much from others and I find new insights everywhere.
—Jim