Does religion have a place in Prog music?

I think that the image explains the concept very well. Whoever thinks to be in the right because has seen the absolute Truth in a book or has been teached to it, belongs to that category. It's more frequent within religious people, but not only. Nazis, Stalinists, Yankese exporters of "democracy" a la Bush... when anybody starts using scribbled words instead of neurons we have this kind of fools. They can be more or less dangerous, but I don't see a big difference between a priest burning a witch, a Jihadist burning a temple of another religion and a bigot denying evolution for creationism. The difference is only in the power that they have. American anti-abortists have killed doctors, they are not different from the Mullah Omar. The Chilean fascists who cut off Victor Jara's hands are not different from Cambodian Red Khmers. 

"Religion" derives from Latin and literally means "conformant to a thing" (re=thing ligio=conformant). Nothing divine in this, just a question of "common behaviour". A British historicist, R.H. Tawnee has analyzed it very well in a book about the Protestants: when the people's mindset evolves faster than the "common sense" the gap generates the impulse to revolution. 

Back to prog: a lyricist can take the inspiration from anything. The important is that it's "inspired". That's why even if I'm an atheist I like Neal Morse and I'm not annoyed by his prayers. I think he's sincere and inspired, so it's ok for me. On the other hand, I can't stand with some Black Metal Satanists who only follow a standard without really believing in what they say. 

Everything can find a place in prog music, then it can be good or bad. Just it.

I suspect I'm of those non-determinants since I've not expressed a view on the question. We cannot dictate the subject-matter of any song, we can only choose not to listen, therefore every subject has a place even if they are not welcome to some listeners.

It is never a safe-play to generalise when it comes to music and lyrics, I do listen to and enjoy some music that uses religion as a topic as much as I do some of those that don't - it simply isn't possible for me to like all secular music so I'm going to be hard-pushed to like all christian music, all buddhist music, all wiccian music or all music that praises maharishi-mahesh-yogi-guru. As a post-theist it's all fiction to me so one story is as good as any other if it is told well enough; the problem that "the message" type lyrics are prone to is often good story-telling and good lyric-penning takes second place to putting the message over. This (I suspect) is what people mean by "preachy" ~ when the song becomes a hard-sell for the message, even Roger Waters can over-sell the message in his lyrics. [I could argue that evangelism is by definition and by nature a "hard-sell" of christianity]. It can become off-putting when it tries to sell me something I don't want but if I can ignore the sales-pitch then I can go on to enjoy the presentation, I don't have to take it personally or agree with the sentiments being expressed. I can happily listen to Rob's music without accepting his thoughts and ideas on religion just as I can enjoy (to some extent) hearing Jon Anderson sing without even attempting understand whatever it is he is singing about. Contrarily, I have tried to like Saviour Machine - on paper everything about it is indicative of something I should like - yet I don't.

With regard to Morse, as I said earlier, I've not heard anything he's done since leaving Spock's Beard - you could say I have voted with my wallet though that choice was not wholly made due lyrics I hadn't heard and certainly not by his conversion to evangelism, I was losing interest in SB and Transatlantic prior to that and since that decline continued with Feel Euphoria and Octane I didn't see the need to explore the direction Morse was taking as a solo artist. If he wants to express his religion in music then that's fine by me, I don't have to listen to it if I don't want to. 

Sorry but you went too far there. I am not too bad at English, Spanish, Italian, French, Dutch or Catalan, but although lyrics can certainly add value to the music, I would never say that the music I enjoy the most is so because it has lyrics. No way.