Alan Page, on his Microsoft blog, asked whether it was possible for one person to be two things. Given who I am and what I do, that's a question I ask myself a lot. I've got a BA and an MA in theology, but I've worked full-time in technology since 1992, without ever (quite) losing my taste for theological and biblical studies.
The good news for people like me is that there are folks who've managed to succeed in more than one field. Abraham Kuyper was an important theologian, a university president, and prime minster of the Netherlands. Albert Schweitzer was a noted theologian, musician, and physician – oh, and winner of the Nobel Peace Prize. G. K. Chesterton was as acclaimed for his novels, literary criticism and political writings as for his Christian apologetics. And Blaise Pascal is as likely to be referenced by mathematicians as by theologians. In other words, the stifling and arbitrary divisions which academic study has inserted into all fields of knowledge are a largely modern invention, and may still (perhaps) be overcome by the occasional genius.
But I have to imagine that it's hard to master more than one field, even for geniuses, and I can't really believe it's possible for the rest of us. I would be a better CTO if my nightly reading had more Knuth and less Calvin, more McConnell and less Lewis. But I don't even have enough time to do all the reading in just one field. There's too much to know about any subject worth studying to be a universal expert. Even the smartest tech guys I know are not, say, database experts in general. At most, they're experts in one or two database systems, and dabble in the rest.
Similarly, I'm well aware that I'm not a real theologian. I can read Koine Greek, and dabble in Biblical Hebrew, but I've forgotten the very little Latin I ever knew. I've only skimmed the Fathers, my reading of 20th century theologians is pathetic, and I get intimidated when I'm around someone who's actually knowledgeable about any of these subjects.
But if I only focused on one thing, I think I'd be living a less interesting life. Lewis once wrote somewhere (can't find it at the moment) that it was astonishing how young he was when he found himself saying with a sigh, "I'll never have a chance to study that." And if you want to be as good at the subject in question as Lewis was in his (which was literature and not theology, as I suppose everyone knows), he's right. But if you're content to explore where your reading takes you, and one day find yourself reading about Israel's modern history, and the next reading about her ancient religion, and the next abandoning it all for a fascinating book on statistics: how could your life not be interesting?
And the best thing about being a universal dabbler is the ability to have interesting conversations with almost anyone I meet, even if I'm asking more questions than I'm answering.
As Chesterton famously said, "If a thing is worth doing, it is worth doing badly." Or in the same book, "The world must keep one great amateur, lest we all become artists and perish."