Some years ago, an Anglican bishop was asked on television how he would deal with a young couple who were having sex outside marriage. "Well, I wouldn't want to condemn them," he said. "Instead, I'd like to get alongside them." It is a wonderful self-parody of Anglican attitudes: gentle, unworldly, non-doctrinaire, comic in its earnest high-mindedness. One takes it the bishop would be rather more ready to condemn the torturers of Abu Ghraib. Or would he climb into bed with them too?

Richard Holloway, former bishop of Edinburgh, is acutely aware of human cruelty and corruption. Between the Monster and the Saint contains a description of 18th-century torture that tender-minded readers may prefer to skip. Holloway is that rare kind of liberal, one conscious of the blind forces that limit our freedom and secretly mould our destiny. Yet he, too, suffers from excessive open-mindedness. He portrays a world crying out for decisive action, but prefers honest confusion to steely conviction. He dislikes the "cut and dried finality" of the Last Judgment, preferring the more "calibrated" idea of successive reincarnations. Even heaven is a step-by-step affair. One is reminded of the Englishman who remarked that the country would indeed change over to driving on the right sooner or later, but would do so gradually.

Like socialism for Gordon Brown, religious belief is largely degutted of content. At one point, Holloway complains in man-in-the pew style that "it is never easy to figure out what [Saint] Paul is getting at"; but given his preference for the cloudy over the precise, one would have thought this was to be commended. Truth comes down to a spot of this and a pinch of that - a dash of Buddhism, fragments of Andrea Dworkin (of all ferociously illiberal writers), a few select pickings from a Christianity the author no longer really believes in, and a strong dose of animal rights. Holloway spends an embarrassing amount of time mourning the death of a beloved old dog, and in his cosmically inclusive way sees heaven as "heaving with turkeys, chickens, pigs, sheep and cattle". But since he doesn't believe in heaven anyway, this insanitary condition poses no great problem.

Holloway is guilty of the therapeutic fallacy of believing that what matters is what makes you feel good. It seems he no longer believes in anything as distastefully definitive as Christianity, but he is far too decent to rob anyone else of their faith if they find it consoling. Does he feel the same about a belief in voodoo or capital punishment? Is it all right to put your faith in goblins, not to speak of Goebbels, as long it helps you along life's way? The human soul, we are told, is a temporal rather than eternal affair - more like "a holiday in a friend's cottage, or a book we've borrowed from the library". Spirituality is all very civilised, suburban and non-metaphysical - in short, all very English. In contrast to this middle-of-the-road mildness, there is something refreshingly bigoted about Christopher Hitchens's claim that all religion is disgusting and should be wiped from the face of the planet.

In reflecting on evil and suffering, death and sexuality, Holloway combines high-minded cliche ("the mysterious complexity of being human") with some genuine shafts of insight. The book's homespun, middlebrow wisdom will go down well with readers who prefer their philosophising to be more anecdotal than analytical. Its Anglican sensibility is too innocent of satire and polemic, too wary of confrontation to address the human ills it identifies. The Jesus of this volume is far from the angry gospel figure who comes to bring not peace but a sword, threatens to tear families apart, divides truth from falsehood, and champions the poor against the rich.

It is true that too much belief can be bad for your health. Despite its blandness, Holloway's brand of faith is infinitely preferable to the brutal dogmatism of the fundamentalists. If some parts of the globe believe too much, however, other parts (the west in particular) believe too little. Holloway feels more at home with "the cloudy glimmerings of myth rather than the diamond-sharp clarities of religion or science". He does not see what a privileged case this can be. Former bishops of Edinburgh may be sceptical of truth and clarity, but there are those struggling with oppressive powers who cannot afford to be so cavalier.