In the United States, the Christian vote is a powerful electoral force - and may even have been the decisive factor in George W Bush's re-election as president.
By Brian Wheeler
BBC News political reporter
But in the UK it remains a largely untapped resource. Politics and religion are, for the most part, kept in separate containers.
Mr Craig believes in 'family values'
"We don't do God," Alastair Campbell famously commented when asked about Tony Blair's Christian faith.
When asked last year by BBC journalist Jeremy Paxman, if he prayed with Mr Bush, Mr Blair could only shift nervously in his seat and duck the question.
It is largely left to fringe parties, such as the Christian People's Alliance, to represent the Christian viewpoint at the ballot box.
"We do do God," the CPA's newly-elected leader Alan Craig says, when we meet at the group's tiny offices in Westminster.
Mr Craig replaces Ram Gidoomal, the businessman and philanthropist, who polled nearly 100,000 votes at the 2000 and 2004 London mayoral elections.
Most of those votes were from members of church congregations, Mr Craig says, but he is anxious to broaden the CPA's appeal to other groups.
He says he wants to build the CPA, which was formed in 1999, into the UK's first Christian Democratic party, of the type found across Europe.
Religion is moving up the political agenda in the UK, he argues, and the country's Christians have been ill-served by the main political parties.
Thanks to an influx of immigrants from less secular parts of the world, the churches in the East End of London, where he has been a councillor since 2002, are "bursting at the seams".
People are hungry for spiritual guidance and feel alienated by the "spin and control" of the Labour-dominated local administrations, he claims.
Mr Craig, a 58-year-old former businessman with four young children, became an evangelical Christian 23 years ago.
As the only non-Labour councillor in Newham, he is the official opposition and has been a persistent thorn in the side of the local political establishment, particularly on the issue of redevelopment.
He has campaigned against the re-housing of council tenants to make way for new executive housing.
It is a classic example of the CPA's Christian values in action, he argues, standing up for local communities in the face of bureaucracy.
He claims to bear the scars of struggles against New Labour "political correctness" and anti-Christian prejudice in the borough.
He tells the story of the Christian community centre he ran in the early 1990s which he says had its council funding cut after it refused to provide a venue for Koranic classes and "Lesbian assertiveness training".
This was a clear case of "Christophobia," Mr Craig says, something which he says is on the increase in public life in general.
George W Bush is a born-again Christian
Although its "roots" are Catholic, Mr Craig says CPA members belong to a wide range of Christian churches.
He also claims support from "moderate" Muslims and Sikhs.
"We may not agree on matters of faith, but they support us as a party, because they like our values."
Asked to define his party's political stance, Mr Craig says it is "right wing on family values and left wing on issues of social justice".
It stands for compassion, respect for life, "wise stewardship", reconciliation and empowerment.
At times, Mr Craig espouses the sort of localism that would not sound out of place coming from a Liberal Democrat or, in their more expansive moments, Michael Howard or Tony Blair.
The difference, he argues, is that the CPA's policies are informed by Christian values.
But he is careful to avoid the censorious tone of the fundamentalist right.
"We believe family values doesn't just mean two parents and two kids. It actually means the whole gamut of values."
Pressed about what this actually means, he talks about parents "taking responsibility" for their children's behaviour and his horror at the recent case of a schoolgirl offered an abortion without her parents' knowledge.
The CPA is vehemently anti-abortion, or "pro-life".
It is also decidedly sniffy about divorce. "It's better if it doesn't happen," says Mr Craig, although, he adds hastily, his wife is a divorcee.
On sex before marriage, he says "we would say chastity is a good idea".
And he would raise the gay of age of consent to 18, but is anxious to "protect homosexuals from violence".
The church's teaching on gay sex is that it is "a sin but not a crime," he argues.
The CPA is probably best known for its promotion of faith schools.
Not surprisingly, Mr Craig rejects suggestions that such institutions can divide communities, arguing they lead to higher academic standards and greater tolerance.
He is realistic about the CPA's chances in a general election, where the first past-the-post system mitigates against smaller parties.
It will concentrate instead on contests with proportional representation, such as the Scottish Parliament, the London and Welsh assemblies.
And, of course, local councils, although he admits it may "take decades" to remove Labour's grip on power in the East End.
But how does his Christian philosophy of turning the other cheek square with the often grubby world of local politics?
In a recent pamphlet, Mr Craig described "town hall bosses" as having "all the integrity of a dog on heat".
But this does not qualify as a smear, he argues, because he was referring to the party bosses rather than named individuals.
"I would never attack (Newham's elected) mayor personally," he insists.
He admits he is making a fine distinction but believes it is important to "speak the language of ordinary voters".