* I doubt seriously Engel to be "Christian-friendly". There is a great difference between using Christian-faith as source of inspiration and being truly Christian-friendly.
Speaking as a Christian, the more the RPG uses Christianity as a source of inspiration and especially the more that it uses occult and esoteric Christian derived mythology like demonology and angelogy as a source of inspiration, the more un-Christian I typically find it.
To me, Christian RPGs tend to be those that don't make the mistake of directly exploring Christian themes or if they do so, they do so by very extended analogies or parallel cosmologies that are in the background of something superficially regular fantasy or science fiction - see for example what respectful Christian authors like Tolkien, C.S. Lewis, Madeleine L'Engle, George McDonald, Orson Scott Card, Gene Wolfe, John C. Wright and others are doing. "Harry Potter" of all things is vastly more a Christian setting than Engel.
That's because all religious Christians treat spiritual things as if they are sacred and potentially dangerous. Where an individual thinks you've gone over the line is going to vary by their specific beliefs. Does VtM go over the line by linking to the Cain story and can you play the game in such a way you ignore it? Does Pendragon go over the line by referencing Christian beliefs and religion and can you play the game anyway in a way that is respectful? Does D&D go over the line by bringing in early modern demonology and witchcraft as sources of inspiration, and can you play the game in such a way that you remove those references? Does "Dogs in the Vineyard" go over the line by directly taking inspiration from Mormonism and could you play it in such a way that it was respectful anyway? Is any game involving the practice of magic going over that line? These are all matters of religious debate. I bring them up not to open them for debate, but solely to show that the concept of "Christian RPG" is very nebulous and that the more Christian references you see the less likely it is that it qualifies and the more likely it is that its overtly offensive.
Thus RpgPub's list of "Christian RPGs" are to me the list of 95% of the most un-Christian RPGs on the market, and if you wanted to make a list of what I don't play that would be on it and the rest of the list would be heavily occult inspired RPGs.
Christian friendly RPGs tend to be things like Boot Hill, Top Secret, Gamma World, Marvel Superheroes etc. where spiritual things can be completely backgrounded from play precisely because play isn't considered a safe way to address sacred things. And then on top of that, how you play those games is going to be a topic of debate. If you play say Boot Hill with protagonists that are villainous killers that's going to make some people uncomfortable. Or if you play the game in such a way that you aren't at least dealing with themes like redemption and the wages of sin, that's going to make people uncomfortable. On the other hand if you do do that, things that would not necessarily strike a non-Christian as being Christian can be surprisingly Christian to a Christian audience. You could for example definitely play a Christian inspired Blade Runner game, without any mention of God at all.
A good resource on this is the youtuber "Servant of Shiloh" that runs the channel RPG Elite. Pretty much anything he considers safe to play is going to be uncontroversial to the majority of a Christian audience.
It's been a bit of a disappointment to me that the original poster hasn't participated in this discussion, because I consider it an important one. I don't know what the original poster was really asking. Was he a Christian looking for advice on what to play, or a non-Christian GM wanting to incorporate Christian friends into his gaming in a respectful manner? That is how I've taken the conversation. But, if he was a non-Christian looking for advice on what RPGs were inspired by Christianity and had made that explicit, I probably wouldn't have engaged with that topic at all.
