Cometh the lockdown, cometh the Cumberbatch moment. We had been wondering how long we could persist in a state of digitally-transmitted theatre without a twist of Cumbers. Despite his prolific screen presence, it is hard to get a glimpse of our greatest living Sherlockian on stage — he has only appeared in two major productions since the early 2000s.

I reviewed him as a frenetic Hamlet at the Barbican and missed him in Danny Boyle’s spectacular Frankenstein at the National Theatre in 2011 — a production which saw Cumberbatch alternate with Jonny Lee Miller as the monster and his eponymous creator. The National’s NT Live broadcasts (via YouTube to our lockdown sofa stalls) bring us both versions, skilfully adapted by Nick Dear. If this seems like a twenty-first-century plundering of classic prose works for cracking plots, this one is only 200 years behind the première.

The Fate of Frankenstein was a swift adaptation of Mary Shelley’s Gothic novel. “Lo and behold! I found myself famous,” she mused after slipping into the theatre unnoticed. Her “monstrous offspring” was enjoying “prodigious success as a drama … in the early performances all the ladies fainted and hubbub ensued!” As it did in subsequent stage incarnations in Paris and New York.

If the iconic 1931 film version is cast as a creaky warning against transhumanist shenanigans, the Boyle/Dear version places the closeness of the Creature and his creator at the heart of the action in a more tender incarnation. In that sense, it is closer to Shelley’s sympathetic rendering of the monster’s self-knowledge and despair at being a man who is also alien to humanity. He reads Milton’s Paradise Lost and sees himself born from Adam — but also the fallen angel: “God, in pity, made man beautiful and alluring, after his own image; but my form is a filthy type of yours.”

The blinding metaphysical ambition of Frankenstein is stunning — even in translation to the small screen, with the Creature’s “birth” magically realised in a choreographed sequence, a tribute to Boyle’s cinematic attention to visual grandeur as the twitching gestures of a newborn bring forth the strange homunculus. The dramatic arc of a terrifying yarn aside, one reason Shelley’s story moves and frightens us in an age of advanced machine learning and deep fake technology is that it prompts us to consider our understanding of the relationship between the Almighty and man and the eternal temptations of its boundaries. Cumberbatch’s pale otherworldliness makes his Creature a vulnerable, blood-streaked thing, driven towards his own destruction and into the realm of evil by virtue of human moral neglect.

It might sound churlish to wonder why contemporary writers shy away from the metaphysical inquiries that brought forth the English Mystery Plays as well as Marlowe and Goethe’s Faust, long before Shelley channelled Gothic horror and Samuel Beckett wrote his deconstructed “God” play, Waiting for Godot.

But the National’s Frankenstein also highlights a gap in contemporary theatre and the way it skirts awkwardly round the big questions that religious belief poses.

Perhaps this reflects the secular nature of theatre audiences and the general retreat of religion from national life. If, for example, you wanted to find thoughtful drama writing on Islam and surrounding tensions with Western culture in years when this has been to say the least a fruitful topic, the nearest to a standout moment on the British stage was the American writer Ayad Akhtar’s multi-layered play Disgraced, which explored the identity crisis of a young Muslim professional in a Jewish law firm and his growing alienation from selfish, self-advancing society. It is a cracking story, challenging to all the belief systems it touches, but its only UK outing was at the fringe Bush Theatre, Shepherd’s Bush — despite garnering a Pulitzer prize in 2013. Theatre backers tell me that this and similar subject matter offers low returns — i.e. audiences run scared of it.

But that can’t be the whole answer, since TV drama has taken a shine to religion and its extremes to some acclaim recently. Messiah is the accomplished single-series Netflix thriller about the cat-and-mouse entanglement of a mysterious “hot preacher”, Al-Masih, who may be the Second Coming of Christ or, to channel Monty Python, “not the Messiah — just a very naughty boy”. I thought Mehdi Dehbi, a mesmeric young Belgian actor, riveting in his role as the ambiguously bewitching healer, not least because it reflects the hardest call for believers: who to trust to spread the faith, without becoming dupes, manipulated by the cynical or opportunistic.

Messiah turned out to be a fleeting apparition. Stories of sensitivities being riled in the Middle East by its content, with criticism of scenes filmed at sensitive sites, were cited as a reason for not bringing it back. So I turned to another Netflix drama in Unorthodox, the closely observed story of the clash of traditional beliefs of the insular Hasidic Satmar community in Williamsburg, Brooklyn. The story is based on Deborah Feldman’s autobiographical account of fleeing the ultra-Orthodox clan and moments of wincing comedy. Esty (Shira Haas, above) is palmed off in convenient marriage to a nice-but-dim husband, so in hock to his mother that she arrives with sex tips for his new wife.

Unsurprisingly Esty makes a break for, of all places, Berlin, where she falls in with a group of musical students so nonchalantly progressive that they can have no idea what she is escaping from and why there is regret as well as vast relief in leaving a closed community. It wouldn’t exactly make one rush to join a life in the permanent lockdown of the Hasidic world, but it shared the intensity and tightly-bonded nature of a world most of us see only in passing. Where the screen at least sporadically dares to tread, the stage remains frustratingly coy. Inevitably, drama about religion will divide audiences and arouse passions about the representation of religious communities.

In an age of wilting commitment to free speech, it takes some bravery to deal with that. But when it neglects the passions, aversions and oddities of religion, theatre misses something profound about the eternal interplay of angels and monsters within us all.