I agree, but I'd add that most "Christians" throughout the religion's history haven't been authentically Christian in that they haven't emulated what the Jesus of the gospels tried to do. But if that's so, it becomes tenuous to speak of "authentic" Christianity.

I've said that what's crucial to Christianity is just its countercultural, moralistic, apocalyptic aspects. But those became irrelevant in the fourth century when the Jesus movement became an empire's state religion. From that point onwards, anyone being authentically Christian in the sense of taking up a countercultural, Jesus-centered perspective was practically accidental. Inauthenticity became the religion's norm, which is somewhat paradoxical and is what makes Christianity arguably the world's worst (most offensive) religion.