How about: apostasy--a standing off, and or turning away/falling away from The Truth.
This is not much different from your previous definition. The Greek word
apostasia from which we get "apostasy" occurs twice in Scripture. In Acts 21:21, the sense is apostasizing or falling away from a specific body of doctrine, that of Moses. In 2 Thess. 2:3 it also occurs, but is ambiguous. If you continue to define it your way instead of as the falling away from a specific body of truth, you then can call whomsoever you wish "apostate"--and you appear to do that in this post.
The Book of Jude has a lot to say about falling away--See vss. 3,4. The whole 25 vss. is a treatise on apostasy.
Of course. But what does that have to do with Christmas? How is celebrating Christmas apostasizing in any way, shape or form?
Falling away from the Truth about Baptism and the Lord's Supper is still the crux of what separates the New Testament Churches from the apostate churches. Rejection of baptismal regeneration and infant baptism has meant the death for a multitude of Real Christians--martyred by apostate Christians. The apostates are still in charge--via the god of this world. The apostates also wrote and revised The history of The Church. We live in a world of ecumenism--many folk scoff at making a stand for such things. How soon we forget.
Again, totally irrelevant. And your vague definition allows you to call "apostate" Bible Presbyterians and anyone else you don't like, including, I suppose, some of us here on the BB if we celebrate Christmas.
Re: Church History midterm. Thank you for posting.
You are entirely welcome.
Many of the references go back to early fathers and others not so early who may or may not have done some serious revision of the facts. Whatever the "holy fathers" may have written seems confusing and contradictory to scripture. These apparently highly educated gentlemen were trying to find harmony between Greek philosophy, mythology and other pagan practices(the Mass of Christ would fall into this observation). Sola Scriptura was in effect long before Luther was born.
This is extremely broad. There were many "church fathers." It's quite easy to call some of them apostate without specifying.
In the 4th century Constantine, the Great, saw a sign: in hoc signo vinces; this resulted in the marriage of an apostate church(es) and the State--they also controlled the libraries.
This is all irrelevant to the discussion at hand, true though it may be.
Someone is being brainwashed--probably us.
Sorry, not me.
Please do not take any of this personally. I am just pointing out some observations noticed in studying World History and Church History for thirty years.
Even so, come, Lord Jesus.
I don't take this personally, just puzzledly.

Your assertions are vague and unfocused.