So devoid of charm is the man at the heart of Drew Pautz's play, it is a wonder that we care as much as we do about his crisis of conscience.
Michael (Jonathan Cullen), you see, is an everyman. Which in this case rather means he is not quite anybody. He is a husband, Christian and envelope manufacturer. And he is gay too, though he would much rather he was not.
In this, his National Theatre debut, what interests Pautz are not one but two crises of conscience - that of an individual Christian and that of Christianity. We open with the latter and with white Western and black African church leaders struggling and failing to reconcile the progressive (Western) and traditional (African) wings of the religion.
Matthew Dunster's well-acted production is at its most vibrant when African grudges and Western condescension sits in the room like the proverbial elephant while two sides who have a history of inequality attempt to negotiate as equals.
The issue here, argued over by a clutch of clergy, is unnamed, as is the African country in which the meeting and the first act takes place. But it is clearly about the extent to which the Anglican church reconciles its irreconcilable differences over its attitudes towards gay people. This is Twelve Angry Men (with one woman), except with God as their only witness.
Sitting at the edge of the stifling hotel conference room in which the meeting takes place is Michael, a lay volunteer who serves as an amateur stenographer, tapping out the arguments on his laptop.
When the action moves to his hotel room, we join the scene just after Michael and Fiston Barek's outwardly polite and inwardly angry hotel porter Joseph have had sex. And again, that issue - where two people attempt parity in the knowledge that one is much more equal than the other - hangs oppressively in the air-conditioning.
How this event is going to play back in the room of church leaders, where Joseph serves coffee, is never explored. Instead Pautz wrenches us to Michael's torpid and childless marriage in Britain where we follow how his sense of guilt drives his increasingly evangelical and destructive faith.
There is a dramatic price paid for this change in setting. Pautz's play becomes smaller in scope. Where earlier the play promised to tackle the very core missionary values of Christianity, instead we become embroiled in Michael's domestic misery. Until Joseph appears (we do not know how he got to Britain) the play has become a sort of Who's Afraid of Virginia Wolf only with less wit, less love and, crucially, less mutual contempt.
It is a turn from which Love the Sinner never fully recovers. And it leaves Pautz searching to match the conflict he so effectively found in the first two scenes.
Barek is terrific as Joseph, flashing anger and sensitivity, but Cullen has an uphill task. Michael is a man with boring written into his DNA. His attempts to explain his faith to his sceptical employees and love-starved wife amount to little more than embarrassed mumblings.
In this, Pautz may very well be reflecting a truth. Faith is possibly the hardest thing to articulate to people who simply do not believe. But there is a price to pay in constructing a play around a confused man who can barely identify let alone express the forces that are tearing him apart. And Paultz's play pays quite dearly.
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