[user3939382]

Rather than saying “it’s origins are x” which reads as if it’s either wholly or primarily based on x, I would say “it’s origins include” or something to that effect. To say “it’s origins are” doesn’t acknowledge the weight of Christian influence on the current tradition, as if it was perpetuated without being majorly changed.

As Christianity spread, holidays and traditions from many parts of the world were subsumed by it. The history of the Church showed that it’s easier to change people’s religious beliefs than some of their cultural traditions. If theologically insignificant elements of a pre-existing pagan tradition got rolled into a Christian holiday that doesn’t mean the holiday is “actually pagan” or observers are giving some deference to a pagan god.

That may not have been your message, but I wanted to point it out because I hear that very often by those who apparently have some axe to grind with the Church and come off as if the history of some Christian holidays is a big secret they uncovered.