Vahn grew up with the Ecclessiarchy being built and such over the last 1000 years, he should be rather content with it at this point. Unless he disagrees and is hating on it. While chapter-to-chapter opinion may differ on that matter, the majority of mankind wants the church to stay. Look at Seelenbrand and many other Astartes who come to accept it. Sure they don't see the Emperor as a god, hell not even Seelenbrand sees him that way. But it is a mere way to cope with regular people's lives since they barely get over 70 years old with all this war and shit, and so they want to know there is more after death than just curtain call. Especially considering that chaos was, probably still is, luring a lot of those peeps with 'immortality' and such, things that the Emperor is not giving them. At the very best, you traditionalists are the traitors & heretics, lol.
Like Bjorn the Fellhanded said "God-Emperor? Calling him a god is why this mess started in the first place."
I love the selfishness of all of your Astartes-characters. None actually thinking for a heart beat about the normal folk which actually ARE the Imperium. The Astartes all compared are perhaps 1000 x 1000 people so 1 million, compared to the TRILLIONS of people that actually are normal human beings, lol. Oh the humanity.
I came back at a good time. Heheh does any of the Astarte realize more infighting could weaken the imperium if its big enough, especially if Astarte get involved.
Yep a Champion that is just trying to go home and lead but has to deal with some idiotic babble between a chaos lord and an Inquisitor.
Claudius is putting faith in humanities strength and will to overcome. Not pushing them from mind. The Emperor believed them to be the greatest for a reason, and that reason was not Astartes. That is what Claudius is defending.