You wouldn't think it, but they encounter a lot of churches in their line of work. Churches, temples, synagogues, mosques, cathedrals, perched on mountaintops, nestled in forests, tucked away in bustling cities or sleepy little hamlets. For whatever reason, the extraterrestrial nasties in this universe seem drawn to these structures, these holy places.
The Doctor has theories about the sort of psychic energy that worship produces, the hormones excreted by various beings when they experience things like awe, wonder, love, hate and fear; oh yes, he has his theories, about those experiences and the sorts of creatures drawn to them. But before he bores Rose to tears with said theories, he has a question.
"What do you believe in?" he asks, and she shrugs. "Lots of things," she replies, and leaves it at that.
It's a rather a broad question, he realizes. Lots of answers could get swept up in that net. He leaves it alone, for now. He can always fish again later.
He tries again a few weeks afterward, when a mission leads them on a chase to Thailand. With the help of several monks, they rid a local Buddhist temple of its nasty Carelian arachnid infestation—promising, of course, to transfer the arachnids to a safe habitat afterward.
The Doctor thinks they should probably stomp the spiders and be done with it. See how they like it, being terrified before they go splatunder someone's shoe. The arachnids hurt quite a few people, terrorizing monks halfway across the world before Torchwood finally tracked them down, and they made a lot of folks sick in the process. The Doctor has little patience for things that hurt people, anymore. (Probably this is the whole "blood and anger and revenge" bit that the other one was blathering on about.) But the monks were the ones affected, and the monks asked that their lives be spared.
Because of their convictions. Because of their beliefs.
So he asks Rose again. What does she believe in?
"You mean like a religion?" she asks.
He does, sort of.
"Haven't got one."
He frowns. No, that isn't quite what he's looking for either. But she doesn't volunteer anything more, and he doesn't push.
(It's an experiment, he thinks. He's asked the question and done his background research. Now he just needs to modify his methods. Tweak words and nudge factors until he gets his answer, until he can draw a reasonable conclusion, until she tells him what he wants to know.)
"Most humans believe in something," he tells her one day, when they float past a mosque in downtown London. He looks out the zeppelin window and swirls his champagne in its glass, a hundred-pounds' worth of Pete's best about to disappear down his gullet without so much as a blink. "Doesn't have to be a religion," he continues. "Tricky things, those. Easily stagnated."
"Also occasionally full of stuffy old geezers in funny old clothes," Rose adds.
"Also, that," the Doctor agrees. "What about you, though?"
Rose sidles up next to him, looping her arm through his. "Don't worry. You're the only stuffy old geezer for me," she teases.
He frowns. She grins and kisses him on the cheek, soft lips leaving a vague heart-shape behind. A signature in lipstick. A declaration in red. She saunters away, throwing a coy look over a shoulder partially exposed by a backless gown and that, that's an expression he's gotten to know very well over these last few months. A familiar request in this strange new universe. Rose leads him to an empty loo at the back of the aircraft and when the two of them emerge, he has lipstick smeared in all sorts of other places, as well.
It's a diversion. (Though a welcome one.) He knows this.
(Well, he figures it out later. His brain has been around for a good long while, but his body hasn't, and it's easily distracted by tempting smells and pillowy curves and teeth grazing the shell of his ear.)
"What about you?" she asks, at the steps of a small church near Pete and Jackie's manor. Tony is singing in the children's choir this morning, got a solo and everything. That is the only reason either of them are setting foot in this building, and the Doctor's having trouble even with that—carpetsand drapes and mortgagesare all very good and well, but that's about the extent of his domestic capabilities, and this is just a bridge too far. Rose has to tug on his hand and remind him that this is for Tony, no one and nothing else, and they can go out for chips and ice cream after.
The Doctor doesn't have a chance to answer her question before they're ushered to a pew, and then people are standing and singing and sitting and listening and some old fellow is drawling on endlessly and he's fidgeting and constantly eying the clock even though he knows exactly what time it is, down to the second, because try as you may, some things never leave you. His right knee bounces madly, impatience buzzing through his skeleton. It's a little bit better when Tony shyly performs his piece in front of the congregation, but then it's right back to the jump-jump-jumping. The Doctor knows he's making the whole pew vibrate and Rose puts her hand on his knee but she doesn't stop him, just scratches at his leg through his trousers in an absent gesture of reassurance. That's enough for now, the weight of her pressing into him, reminding him that this will be over soon and it'll be worth it to see the happiness shining on Tony's face afterward.
But then the sermon, which started out as a harmless, if a bit dull and historically inaccurate, retelling of Joseph and his technicolor dreamcoat, suddenly veers into something else. A story about family and pride, love and betrayal, hardship and faith somehow transmutes into a lecture, and suddenly hate-filled words are dripping from the pastor's mouth. Words like "sin" and "the Devil," "sexual perversions" and "moral degradations", "anti-life" and "feminist propaganda," "entitled youths" and "beware the temptations of the world". Each passing word makes the Doctor's blood boil more and more for reasons he can't quite describe.
Now Rose's hand on his leg is digging fingernails into his flesh. He can tell by the tension of her arm and the muscle grown taut in her jaw that she's just as upset by the words as he is, just as angry at these petty humans spewing their narrowminded worldviews in a stream of hurtful bile.
The Doctor wants to stand up. He wants to argue. He really wants to speechify. Wants to put that horrid red-faced little man in his place, tell him what a showdown with the Devil is really like. Show the attendees of this church what a real sinner is truly capable of.
Instead, he laces his fingers with Rose's and he pushes up off the pew and pulls Rose along with him. Jackie faintly protests; both of them ignore her. The Doctor can feel Rose's pulse hammering in her fingers as he drags her out of the building. A thrill runs up his spine and he wonders if she feels the same way.
A few moments later, bodies and mouths colliding as he pushes her up against the cold stone wall, he finds out.
(The answer, of course, is Yes.)
If that was the sort of thing that will send him to hell, the Doctor thinks afterward, then he'll go without a fuss and with a smile. Because that was so much better than any religion could ever be.
(He knows that he would make a very bad god, but Rose made a pretty decent goddess once upon a time. Perhaps he is a religious man after all, he thinks, because he would gladly worship her. Her body would be his temple, her sighs his blessings, her kisses and touch, his reward; when she draws him in for a kiss, he swallows the benedictions from her lips.)
He doesn't even consider the possibility that he's looking at her through rose-colored-glasses, or lenses colored after any other flower for that matter; to him, she is the very best of humanity, and only a little of the worst, all poured into a magnificent form that laughs and swears and loves and wants and does. His words are hardly songs of praise, soft and shy as they are while the two of them wait outside for the church service to end, but if she can make them out, she'll know he's saying words of gratitude. It's a lot of pressure to be someone's friend and lover and salvation and conscience all wrapped into one, and your own person besides; he plans to say thank-you in all the ways he can imagine.
Rose doesn't ask again what he believes in.
On a bitter winter day some time later, the Doctor watches a monastery burn down from a fire of his making.
He didn't have any other choice. A Glebring was hiding in the walls, slowly excreting a poison mist that would have killed everyone in the town. (Terrible timing, that; if could have only waited a few months, the translation circuits in the TARDIS would have been ready, and perhaps the Doctor could have negotiated with it a little better.) Fortunately, the Doctor knows that the efficacy of such a mist is greatly diminished when exposed to temperatures above 600 Celsius; unfortunately, such temperatures will also kill the Glebring.
The human inhabitants all survive. The creature in the walls does not, and it, along with several hundred years' worth of history, dies in a fiery blaze in front of him. Yet another thing he couldn't save. Another creature he couldn't reason with. One more failure to call his own.
"I don't think I believe in any gods," Rose says, interlocking her fingers with his, "but I can see why some people would."
He shoots her a questioning glance, and she smiles. "People believe in all sorts of different things that get them through the day, and that's okay," she explains. "Whether it's gods or science or the amazing power of the human spirit, or whatever."
"At least two of those things are a little silly," the Doctor grumps.
"I dunno. I think if it helps you, and you help other people, and no one gets hurt, or held back, then all of it's good," Rose argues softly. "It's good to have something or someone to believe in. Something to give you hope."
"And what about you?" the Doctor asks. "What gives Rose Tyler hope?"
"Oh, all the usual stuff," Rose tells him. "The power of good over bad. The idea that the right side will eventually win. Knowing that you can't save everyone, but that doesn't mean you shouldn't try."
The Doctor allows himself a small smile. He knows that most of this is for his benefit, to soothe the sad sap counting all the things he did wrong instead of celebrating the people who survived—the people who are, in fact, holding hands and praying, and giving thanks, of all things. Their holy place is gone, along with several of their homes and many of their possessions, but they all seem immeasurably happy to be alive. Why can't he be happy if they are? Surely their feelings on the matter are more important than his.
"It's a good list," he says. "But is that everything? Not that it isn't complete as it is."
"Well, there's also logic and reason and science, and the times that none of them mean anything," Rose tells him. "And…"
She quickly grows shy, her eyes casting down to the ground. "And that's about it," she says.
The Doctor knows she's lying.
He doesn't press it. He has his secrets. He supposes it's fair that she has hers, too.