We have an adversary who cares not whether we call paganism Christianity, or if we reject Christ altogether- Anything but the worship of our Creator in spirit and in truth.
In 2 Corinthians the apostle Paul cautions believers, stating: …I am jealous over you with godly jealousy: for I have espoused you to one husband that I may present you as a chaste virgin to Christ. But I fear, lest by any means, as the serpent beguiled Eve through his subtlety, so your minds should be corrupted from the simplicity that is in Christ. For if he that cometh preacheth another Jesus, whom we have not preached, or if ye receive another spirit, which ye have not received, or another gospel, which ye have not accepted, ye might well bear with him.
In other words: Do not go along with it!
No, Jesus was not born on December 25th in a pagan sun worship cave. Those concepts lead us away from who Jesus really was-away from the first four commandments that tell us who our Creator is and how He wants us to worship Him. Pagan worship must only be associated with an imposter-as the Bible states, Another Jesus. Time is the Ally of Deceit.