Once upon a time this was true. Christianity was considered as a quasi-Jewish cult. That's what so outraged the ruling priesthood about Jesus' followers and why Pilot and Annas were brought into the mix.
Jesus'followers-no official Christians at the time-were a band of rabble-rowsing upstarts that were fueling the passion of the people against the ancient gods.

In time they managed to get organized and find money to spread their beliefs...we know the rest, don't we?

Pagans will continue to drown in the mainstream until we find common ground in our beliefs and be willing to "give" a bit for the sake of ecumenism among our traditions.If we cannot find a common voice, if we continue to identify ourselves by our differences, then we will remain in the background. Until then, we can hardly expect to be acceppted by other religions.