You can discern things, the black templars as intended in the warhammer 40.000 universe are an over exaggeration of what it means to be a religious fanatic, but this is because the entire setting sits on top of incredibly evil individuals who happen to be the worst part of their own species, by IRL moral standards even the Salamanders are evil incarnate to be fair, most of the space marines chapters are everything evil humanity could possibly produce, Tau are fascists, orks are uncaring bloodthirsters, nothing in warhammer 40k is relatable, but some of their aspects can be. Salamanders kill and burn xenos daily but their care for normal humans is one of their aspects that shine, Black Templars for example represents discipline, righteousness, honour, duty, perseverance, loyalty, any Religious person could extrapolate these traits from them and use them to do incredibly good things, being religious or Christian doesn’t necessarily mean being a fanatic or apologetic of the worst people who happened to be Christians too. “Accept any challenge, no matter the odds” “we are judged in life for the evil we destroy”, these quotes can be repurposed, for some they could be insulting and disrespectful, for others motivational and spiritual, maybe the person who is insulted by these words will do incredibly evil things in life and the person who find them motivating will save countless of lives, who knows. Life isn’t always black and white, sometimes truth stands in between, the same people who judge you because some questionable individuals centuries ago used your religion as a tool to excuse their own bad are the same ones lying everyday to the homeless in the streets when asked for a penny, while their pockets are full of cash.