Where there is war, there is death, and where there is lots of death, we would expect a discussion of higher powers and afterlife. However, there aren't many religious symbols to speak of in this story. One would think that with so many lives so close to meeting their Maker, that there would be a good deal of prayer. Instead, there are only a few vague references to The Iron Cross (German award for wartime bravery), and not much else. Why do you think there is so little talk of religion in this book?
At times it would seem that the earth itself becomes the higher power that grounds the soldiers and that keeps them sane. As Paul gains more experience on the Front, he begins to consider war and death more carefully. He searches for meaning in the world around him, and we get a crystal clear view of this search. We watch him wrestle with the hell he exists in on a day-to-day basis, and we watch him grasp for things that will help him make sense of the killing that he witnesses. In Chapter Four, Paul realizes the power that the very earth holds. Rather than praying to a god for protection, or thanking a god for protection, Paul celebrates the Earth. Consider his words:
To no man does the earth mean so much as to the soldier. When he presses himself down upon her long and powerfully, when he buries his face and his limbs deep in her from the fear of death by shell-fire, then she is his only friend, his brother, his mother; he stifles his terror and his cries in her silence and her security; she shelters him and gives him a new lease of ten seconds of life, receives him again and often for ever.
Earth! – Earth! – Earth!
Earth with thy folds, and hollows, and holes, into which a man may fling himself and crouch down! […] O Earth, thou grantest us the great resisting surge of new-won life. (4.23-4.25)
The earth has the power to protect and shelter soldiers when they hide in trenches or in holes made by shells. Earth proves to be a match for the man-made weapons that seek to kill men; for, even though Earth cannot fight back, it can protect Paul and his friends. Notice how Paul uses words like "thy" and "grantest" – it's as though he's reciting an old prayer. You could argue that he's praying to the only power that can help him.