This isn't true. I don't think that really happened until it became state religion of Rome.

Early on, sure, but not always.

You can't be attached to and thus in the service of Empire and not be classist. Imperialism is dependent on classism.

The disconnect you're talking about in the essay snaps into a place that makes sense one you realize one thing.

Christians are not followers of Jesus. Using his name isn't the same as adopting and living by his principles. Christians are followers of Paul, the first apostate. Since Paul was a Roman and an agent of Empire, and he organized and gave legitimacy (in Roman terms) to the early church, it naturally followed that Christianity was set on a course away from Jesus very very early on. Still took a few hundred years, but it was pretty much inevitable.