Right, I’m not trying to indirectly make a point about Christ not being likely to have existed or anything, just making a point about the language: Christ’s existence hasn’t been scientifically proven, it’s just that historians agree that it’s a reasonable guess based on the texts that were left behind and mentioned him.
Archaeologists might use scientific methodologies, e.g. carbon dating, to estimate how old a text is, for example, but I wouldn’t consider this scientific proof that someone existed.
Maybe I’m losing the context, when are you using this term? If you wanted a simple term to get the idea across you could just say you’re a “Christian atheist”, no? Most people probably don’t care tbh, so it’s unclear when you need to be making these distinctions. I only say this because “atheism” doesn’t exclude Christ’s secular / moral teachings, and the concern with Christ not being mentioned in a term like atheism makes me wonder why that’s relevant.