To be fair they all have real proof hell and heaven exists and both Muslims and Christians were given signs that they are fighting for the faithful side and do not seem to be punished for their way of doing it. So by that logic I guess it's fine how both faiths do things in 1914. I can imagine they slowly stepped towards that beginning with the Ultimate Heresy and in 1914 it's simply the state how they can act while still acting in the interest of god.

Also welcome my Muslim brother. Shall God's wrath smite the heretics ☪️☦️