In the first century, they were just Christians, now we have to qualify who we are, liberal, progressive, conservative. Prior to the 20th century, we had a Bible, now we must qualify the Bible: interpretive, literal, for women, for blacks, even for homosexuals. You use to be able to say the Bible is inerrant, infallible, now you have to qualify it with full or absolute inerrancy because there are now multiple levels of inerrancy (e.g., partial inerrancy).
What Jesus founded and the apostles grew has become so watered down and divided, it is 99% world and 1% Christian. The irony is that the Christian missionaries used to be sent out from the Western World to Africa, Asia, South America, and so on, now these places are sending missionaries to the Western World. The irony is that Christian apologists spend more time evangelizing their own, they no longer have time for the unbeliever. But in reality, their own are now the unbelievers.
https://www.amazon.com/dp/B07GTQ3M8Q