That's according to history.
An alternate view is that the Roman Catholic Church saved more souls by adapting their pagan traditions to Christian beliefs, thereby making the transition from pagan to Christian less traumatic for the masses.
Of course this is a possible explanation, but whomever takes such a stance ceases to be Christian, as definied by the Bible. So, why should Christians let those who no longer follow the Bible, and no longer Christian, dictate to Christians what is and is not Christian. It's laughable. It's be like me defining what books and teaching are and are not Holy to a Hindu (and being serious about it).
Could we just go back to talking about ETs now?
Sure
Now you've done it. I've taken the bait.
First, I'm not sure what you mean by the statement, "whomever takes such a stance ceases to be Christian, as defined by the Bible." My understanding (perhaps different from yours) is that a Christian believes that Christ is the Son of God, sent to redeem mankind from the sin of Adam and Eve.
Once you've acknowledged Christ as the Savior, you go out and tell others.
My take on the adapting their pagan traditions to Christian beliefs philosophy is that it helped explain Christian beliefs in a way that was easy to understand. For example, the celebration of Spring Solstice and Easter commemorates rebirth both of the earth and of mankind, since man was reborn through Christ's Sacrifice. Just as the earth comes to life every spring, man comes to life through Christ.
The Christian tradition slowly but surely replaces the pagan tradition, and even when a society becomes secular (as ours has), the tradition of an Easter celebration makes the Christian aspect of the day hard to hide (even for the most determined Atheist).
So we have a pagan holiday that was co-opted by the Christians, and the modern-day secularists cannot overcome the religious significance because the holiday has come to represent the Sacrifice of Christ.
Who says God doesn't have a sense of humor?