The chaplain means business. Really, he's a serious guy. If a peasant is dying, you know he'll be on the scene, ready to bandage some wounds. But as his character develops throughout the play, we witness the chaplain growing increasingly frustrated and cynical about the war and his role as a "pastor of souls."
Like the cook, the cook is a part of the (Protestant) Swedish army, but he is not enlisted. He's the regimental chaplain. He also gets treated poorly by the general, who calls him "the old bigot" in Scene II (II, 56). And in return, he seems more than willing to tell the general what he wants to hear in terms of religion. Take this exchange, for instance, when the general asks the chaplain what he thinks about Eilif's heroic deed to steal cattle from the peasants:
THE GENERAL: What is your view, pastor of souls?
THE CHAPLAIN: That phrase is not strictly speaking in the Bible, but when Our Lord turned the five loaves into five hundred there was no war on and he could tell people to love their neighbours as they had enough to eat. Today it's another story. (II, 125-130)
If you didn't catch that, Chap takes two unrelated parts of the Bible—the part when Jesus feeds the multitude and the injunction to "love thy neighbor as thou love thyself"—and uses them to explain why the Bible is basically irrelevant to their time of war. (Check out our "Allusions" section for more on these biblical references).
According to the chaplain, Jesus was able to tell his followers to love and respect one other, rather than, say, steal and eat each other's cattle, because he was able to provide them with enough food. He sidesteps the moral question entirely, reflecting Brecht's well-known adage: "First comes eating and then comes morality." In other words, moral lessons from the Bible are only relevant once other basic needs have been met.
Still, the chaplain genuinely believes that theirs is a war of faith, even if the Bible proves irrelevant for their moral questions. For him, unlike Mother Courage or the cook, the war is not all about profit. It's about power. Proud of his training as a preacher, the chaplain knows a thing or two about power. Check out what he tells Mother Courage in Scene VI:
THE CHAPLAIN: I told you I'm not a woodcutter by trade. I studied to be a pastor of souls. My talent and abilities are being abused in this place, by manual labour. My god-given endowments are denied expression. It's a sin. You have never heard me preach. One sermon of mine can put a regiment in such a frame of mind it'll treat the enemy like a flock of sheep. Life to them is a smelly old foot-cloth which they fling away in a vision of final victory. God has given me the gift of speech. I can preach so you'll lose all sense of sight and hearing. (VI, 193-202)
Here, Chap explains that his preaching talents are being wasted working for Mother Courage. But if we look more closely at this passage, we realize that the chaplain is saying some important stuff about religious power. He doesn't say that his talent is preaching God's word. He emphasizes that his "gift of speech" is able to send men into war, ready to slaughter the enemy "like a flock of sheep." He blinds them with religious rhetoric. He makes them good soldiers.
In other words, the chaplain knows how to give soldiers faith. But it's just as much faith in war as it is faith in God. We find something similar early on in the play, when the chaplain disagrees with the cook about falling in battle. Check it out:
THE CHAPLAIN: Don't give way to your feelings, cook. To fall in battle is a blessing, not an inconvenience, and why? It is a war of faith. None of your common wars but a special one, fought for the faith and therefore pleasing to God. (III, 150-154)
The chaplain initially has faith in the war because the war is about faith. But once the chaplain starts to lose that faith, he becomes a little more critical of those "god-given endowments" of his. It all starts to turn around after the chaplain has spent a while with Mother Courage. He becomes convinced that the war will go on forever, as long as it suits the interests of those in power. Here's what he has to say:
THE CHAPLAIN: […] There've always been people going round saying "the war can't go on for ever." I tell you there's nothing to stop it going on for ever. Of course there can be a bit of a breathing space. The war may need to get its second wind, it may even have an accident so to speak. […] It can suddenly come to a standstill for some quite unforeseen reason, you can't allow for everything. A slight case of negligence, and it's bogged down up to the axles. And then it's a matter of hauling the war out of the mud again. But emperor and kings and popes will come to its rescue. […] (VI, 63-75)
The chaplain is no longer talking about a war that's pleasing to God. This is a man-made machine that is run by "emperor and kings and popes." If it breaks down now and then, they'll start it right back up. This is a war that can go on forever, a war with no God in sight.
After the Chap's cynicism about the "war of faith" fully rears its head in this line, we're not too surprised by the following exchange with the cook, when peace breaks out in Scene VIII:
THE COOK: pulling off his boots and unwrapping his footcloths: Pity the war made such a godless s*** of you, else you'd easily get another parsonage now it's peacetime. Cooks won't be needed, there's nowt to cook, but faith goes on just the same, nowt changed in that direction.
THE CHAPLAIN: Mr. Lamb, I'm asking you not to elbow me out. Since I came down in the world I've become a better person. I couldn't preach to anyone now. (VIII, 171-178)
Here, the chaplain shows a new development in his character. After complaining so much about wasting his talent, now the chaplain seems to have turned over a new leaf. So what does he mean by "I've become a better person"? And why does this mean that he can't preach anymore? Well, maybe after he realized who's really in charge of the war—the "emperor and kings and popes"—he's feeling reluctant to go back to his day job. After all, as an army chaplain he was convincing soldiers to die for God, when all along the war was really a machine of politics.
Then again, the last we see of the chaplain is him back in his clerical outfit. He's heading off to give counsel to Eilif, who's on his way to execution. In other words, the chaplain snaps right back into a religious role. Perhaps the real point is that, while the chaplain has become cynical about war and faith, he has not necessarily lost his faith in God or his sense of duty to help others.