We all know by now that the King James Bible is 400 years old, right? I mean, it has been everywhere. We've had James Naughtie retelling its story on Radio Four, a book and a television series from Melvyn Bragg and, over on BBC Four, Adam Nicolson comparing the book to the Millennium Dome. There have been exhibitions, lectures, readathons and flower festivals. This Sunday, there's even a "Bible Cake" courtesy of Bradford Cathedral, which will, presumably, lead to much wailing and gnashing of teeth.

Theatre has certainly played its part in this cloudburst of anniversary celebrations. Over 69 hours at Easter, all 788,280 words of the King James Bible was read onstage at Shakespeare's Globe, which went as far as to name its current "Word of God" season in its honour. The National Theatre hosts a series of readings of its own throughout October, while the RSC opens David Edgar's new play about the book's conception, Written on the Heart, next week in Stratford. Not forgetting, of course, the Bush theatre's marathon Sixty-Six Books, which opened the new theatre last week and contains 66 new plays by 66 writers, each inspired by a single book within the whole.

So, why has theatre taken up the cause so strongly? It's not exactly been sympathetic to organised religion in recent years. Of the two priests currently on stage in London, The Veil's Reverend Berkeley is a self-styled ghostbuster, while the unnamed one in Phaedra's Love at the Arcola gets down on his knees in front of a prisoner. (I assure you that he's not deep in prayer.) Nor is this a new development: think of the bumbling halfwit Reverend Lionel Toop in Philip King's 1945 play See How They Run.

Cynics might point to theatre's tendency to trade on the currency of anniversaries or the bums-on-seats guarantee of an absolute familiar title, but there's no denying that the King James Bible is a major cultural landmark. The King James Bible was, of course, written to be read aloud, so its natural home is the pulpit or the stage. As Henry Hitchings has eloquently pointed out, it is a linguistic feast, full of rolling rhetoric and freshly minted phrases that have worked their way into everyday speech. In that, it has strong ties with our writer-led theatrical culture.

And theatre has always had strong ties to religion, from the ceremonial play festivals of the Ancient Greeks, full of dei-ex-machina and divine retribution, to the Mystery plays of medieval Europe. These forms are regularly cited or replicated in contemporary practice. Just look at the National Theatre of Wales' Port Talbot Passion.

However, one thing I noticed during Sixty-Six Books – and I'll confess to only having seen 19 – is that those that worked best got inside their source material to make them present-tense. Some, such as Jeanette Winterson's Godblog, applied a literal filter of modernity through the language of social networking, while others – Stella Duffy's The Book of Ruth (and Naomi), Matt Charman's Without Love, for example – excavated the text to unearth the emotions. This is theatre's strength: it has the potential to humanise the Bible in a way that its own objective style of reportage rarely manages. Theatre can bring stories thousands of years old right into the present.