You've probably come across questions like these from others — perhaps at medical school. You may have even asked them yourself. Perhaps they've even caused you to doubt your faith.
My name is Calum and I am a doctor working part-time as a speaker at the OCCA (The Oxford Centre for Christian Apologetics). At the OCCA, we do our best to answer questions like these. Sometimes the answers come very easily, and at other times they are more difficult, but as Christians we don't need to fear the truth. Jesus said, 'I am the way, the truth, and the life' (John 14:6), and entered history in part to show precisely this: that we can test the claims of the Bible and subject them to historical scrutiny.
When I went to medical school, I wasn't sure what to believe about much of this. This was at the time that Richard Dawkins was particularly popular: I had gone to Oxford, his home university, anticipating a barrage of anti-Christian ideas, perhaps even ridicule. And partly for that reason, I went with a very watered-down version of Christianity that looked down at mainstream Christians with scorn and derision. I even set up an alternative Christian Union in my first year to challenge the claims that Christians were so confident about.
I was surprised to find so many Christians at the top levels of academia, no matter what the discipline. Perhaps the most surprising was finding my tutor, the Director of Preclinical Studies and Professor of Anatomy, giving a sermon in chapel about the (literal, bodily) resurrection of Jesus! But there were many more besides.
As time went on, I grew more sceptical of my own scepticism. When I met 'mainstream' Christians, I found that they weren't as crazy or irrational or plain nasty as I'd been led to think they were. They were kind and thoughtful and — perhaps most importantly to me — they had solid answers to the difficult questions.
At university, I began to wrestle with these questions at the highest level I could. I read the latest ideas in philosophy and history, even getting to work with my philosophical hero, Richard Swinburne. After working as a doctor full-time for a couple of years, I went back to Oxford to study bioethics, finding again that the Christian perspective on the dignity and equality of human beings — no matter how young, old, or dependent they are — made the best sense of our most basic intuitions about equality and human rights. At conference after conference, and in paper after paper, I found that the Christian worldview made the best sense of the world: of our beliefs about morality and rights, the existence of the universe, our conscious experience and, most critically, the historical evidence for Jesus' life, death and resurrection.
That doesn't mean that all my questions have been answered — that would almost be too easy, perhaps even suspiciously neat and circumscribed. But we trust people without knowing everything about them all the time. We do so not because we know everything about them, but because what we do confidently know about them gives us a firm enough basis to trust them on the things we're uncertain about. This is what 'faith' is: putting your trust in and investing in somebody not because there's no evidence for them, but precisely because they've given you reason to trust them.
Christianity ultimately hinges on the person of Jesus: Who was he? What did he do? And what happened to him after his death? Again, not only does Christianity have good answers to these questions; any other answers are demonstrably flawed. To ensure I wasn't just naively believing biased Christian apologetics, I went on to do an MA in Biblical Studies, with my dissertation on the historical reliability of the gospels. This confirmed to me what my prior reading had suggested: historians simply cannot plausibly explain who Jesus was and what happened after his death. They have been trying for 2,000 years, and they still do not have the faintest idea of how to explain the evidence, unless Jesus really was who he said he was.
At some point in your studies, you will probably come across Sims' Symptoms in the Mind,  perhaps the introduction to clinical psychiatry. It was written by Andrew Sims, a former President of the Royal College of Psychiatrists. Lesser known, but more important still, is another book he wrote just two years ago: Mad, Bad, or God?  In this book, one of the leading psychiatrists of the last 20 years shows how the radical claims of Jesus about his own identity need explanation. One explanation is true of other people who make the same claims: he was suffering from psychotic illness. But Sims explains how this explanation — perhaps the usual explanation for these claims — simply doesn't make sense of the historical evidence. Not only was Jesus not psychotic, he showed profound mental stability and genius, rivalling some of humanity's greatest minds. Nor did Jesus show signs of being a liar: not least because he was willing to die for what he believed. If that's the case, our ordinary explanations for why people claim to be God fail. Is there another one? Sims thinks there is.
Perhaps that's not enough for someone to believe in Jesus; it's not what originally convinced me. What really stumped me is the evidence for Jesus' resurrection. There's so much to say about this — I recently recorded a 45-minute podcast  on the topic! — but the short story is this: when you probe deep into the historical evidence, there really is no other plausible explanation for how Jesus' tomb was found empty, and for how his disciples — and some people who thought he was evil or crazy — saw visions of him after his death. Grief hallucinations can happen after the death of a loved one; but they are rarely polymodal, even more rarely experienced by more than one person, and virtually never experienced in group settings. No matter how sophisticated the explanations presented for these facts, when you scrutinise them in detail, they don't convince. The life, death, and (ostensible) resurrection of Jesus stand out as an historical anomaly — and yet an anomaly that shattered the norms of the societies preceding it, starting a cultural and moral earthquake, the aftershock of which we are still experiencing. History was never the same afterwards.
Having a background in medicine has given me a unique perspective on these questions including, for example, the question of Jesus' sanity, and the plausibility of hallucinations explaining the disciples' sightings of Jesus. And so, I still practise medicine, while doing a bit of teaching and research at university on these sorts of questions. But I've increasingly moved into speaking and advocacy, trying to show thoughtful, reflective people the sense that Christianity makes, whether historically, philosophically, or ethically. At the OCCA our job is to show thoughtful non-Christians the sense that Christianity makes, and at the same time demonstrate to Christians the richness that can be found in intellectual, evidence-based thinking about faith (without undermining the fact that it is ultimately a relationship!). One of our mottos is: 'No question off limits'. We hope this motto communicates the scrutiny and rigour we try to bring to our work, knowing that even when Christianity is seen clearly, exposed in the cold light of day, it still shines. Indeed, it shines more brightly than ever it did before.
A Portuguese version of this article is available on the website of AEMC - the Christian Nursing & Medical Fellowship of Portugal