[racktash]

I'm definitely no textual criticism expert, but I do have a book recommendation.

The Inner Citadel by Hadot is a great analysis of the Meditations. It explains extracts from the Meditations – such as references to certain people in Marcus's life – with facts we know about Marcus from other sources.

For me personally... While it could be an elaborate imitation, it would raise the question why Marcus espouses views that don't necessarily tie with Christian doctrine. Obviously something about the Meditations appealed to Christians of the time, but if they were inventing it whole cloth, they probably wouldn't have included only one reference to Christianity, which is arguably negative. (Book 2, chp3)

[datavirtue]

Just because you were of the cloth didn't mean you were a raving fundamentalist. Who else was going to house, feed, and protect you and allow you to read and think all day?

[programmarchy]

Both have roots in Platonism so makes sense they would have significant overlap.

[p3rls]

And what is Platonism but Christianity for people who have read a certain preface from Nietzche