Queen Elizabeth I abruptly left while Alexander Nowell, Dean of St Paul's Cathedral, was preaching after letting him and others in attendance know that the sermon was "skant wyl liked of the hier powers". She berated Edmund Grindal, her second Archbishop of Canterbury, for having defended preaching and prophesying. He lost all influence.

His successor in 1583, John Whitgift, and the queen suggested that fewer sermons and the repetition of officially sanctioned homilies would serve the realm better than frequent, impromptu sermons that sometimes dared to criticise the pace of religious reform and might create pandemonium.

Expatriate Jesuits returning to Warwickshire, where Shakespeare grew up, or - more often, through Warwickshire to points north - once they were apprehended, suffered worse than deposed religiously reformed preachers.

And religious separatists among the reformed were hounded into exile or, along with resident and refugee Catholics, were executed. Although Elizabeth professed that she had no intention to "make windows" into her subjects' souls, caution seemed advisable unless a soul could be confident that its piety fully conformed to what the established church's authorities and their queen prescribed.

Given such mixed signals, Shakespeare's apparent reluctance to stake a position on piety, liturgy, or theology - or consistently to agitate against others' positions - (what Alison Shell aptly calls his "confessional invisibility) - is quite comprehensible.

But it complicates nearly all efforts to answer the question asked. Perhaps the only incontestable response one can make is that Shakespeare thought Elizabethan and early Jacobean religions - friars and bishops, papal legates and puritanical moralists, soul-searching soliloquies, convents, and even patches of purgatory – were stuff worth stuffing into his plays.

Rather than exit with that certainty, however, we might sample some of the most contestable and mildly contestable answers. Lately, several of Shakespeare's admirers have argued that his plays and sonnets encrypted messages to Catholics hoping for a resurgence of their old faith. Poor Yorick stood in for Edmund Campion, Jesuit martyr. Lear's Cordelia was Catholicism banished by her father who played King Henry VIII. And, in Midsummer Night's Dream, fairies' field dew called to mind the holy water used to anoint Catholics' marriage beds. It may be unfair to insist such connections are altogether implausible, yet characterising them as contestable should pass muster. Still, that is not to say the playwright did not think nostalgically about Catholicism lost when he thought about religion.

His father John conformed to the established church sufficiently to serve as Stratford's constable, but if a will bearing his signature, now missing, was authentic, the Catholicism that William experienced at home could well have influenced his thinking about religion. Or could his thinking about religion have influenced his daughter Susanna, who married one of the more "forward" puritanical Protestants in Stratford. Shakespeare entertained him in London.

Transcripts of the sermons delivered at St Saviour's, near the Globe Theatre in Bankside (now Southwark Cathedral) survive. Shakespeare's brother was interred there, yet we possess no evidence that the playwright attended - or attended to Edward Philips's, the preacher's, distinctly reformed rhetoric. Hence, attempts to pack trademark Protestant soteriology and sentiments that undermined Catholics' moral theology with ideas about imputed righteousness or predestination into William Shakespeare's plays, sonnets, or imagined conversations on Silver Street where he lodged with reformed associates are, arguably, as contestable as efforts to tease his Roman Catholic commitments from several episodes or characters on stage and from his imagined conversations with known Catholics in Warwickshire, Lancashire and London.

I think it less controversial or, in terms of this short response, only "mildly contestable" to propose that Shakespeare was interested in religious attitudes and expressions that stretched across the confessional divide. Edwin Sandys in the 1580s and John Howson, in the next decade, joined other religious reformers, fuming against prelates, "cunning politicians," whose "gap[ing] for gains" discredited the church.

Similarly, during the appellants' war of words with the Jesuits, but also more generally, Catholic critics of the excessive worldliness of the hierarchy accused highly placed prelates of greed and duplicity. Was Shakespeare mesmerised by the charges and countercharges within confessional camps - and across confessional lines - when he put Pandulph, the sinister papal legate into play or recreated Bishop and Cardinal Beaufort as King Henry VI's "scarlet hypocrite"?

Finally, in a few of Shakespeare's often bewildered and all-too-irresolute characters, playgoers today may discover what Shakespeare thought about the dialectic between faith and doubt that early modern religiously reformed and unreformed preachers and theorists featured in their conversations about the "waves of wo" that washed over souls that could find "no reposing place". The phrases are drawn from Jesuit Robert Southwell's "Prodigall Child's Soule Wracke," but might just as well have come from religiously reformed sermons on despair and consolation, and they apply well to a cluster of Shakespeare's characters' quests for resolve and consolation.

When Hamlet in the graveyard compared petty human "plots" with God's "mighty doings", was he preparing to accept his role in a providential drama ("a special providence"; "readiness is all") familiar, presumably, to Angelo in Measure for Measure or King Richard II, among others, and familiar to those who played them, who either heard Calvinists' sermons or read the Catholics' devotional literature in the religion around Shakespeare?