The problem is they know not what they do. The Sunday Telegraph today reports  on a "Westminster 2010 Declaration" from conservative church leaders.
It's not an original idea. There was a Westminster Declaration which was originally made in 1990 by 1500 Christians  and founded the cross-party Movement for Christian Democracy. Running to four pages it was much broader in scope, it was far better theologically, drew in many more people to support it and was much more comprehensive in focus.
The Telegraph says that the new 2010 Westminster Declaration 
"sets out a broad range of policies that unite British churches".
Three things wrong with that:
1. It isn't broad, but seems predominantly focused on abortion, euthanasia, marriage and the ongoing 'Christian discrimination' obsession (although paying passing lip service to some 'justice' issues)
2. It isn't a set of policies, but rather a set of values that relates to a small set of policy issues
3. It doesn't unite churches. The church leaders who signed it are overwhelmingly conservative in their theology, and the section on marriage alone would split the Church of England, and alienate groups like the Quakers
The declaration fails to mention too some of the biggest issues relevant for this election such as integrity in public life/MP's expenses, constitutional reform, the economic downturn and reform, public services (which John Sentamu writes about in today's News of the World ) migration, criminal justice or child detention (only those "appropriately seeking asylum"!)
But the most fascinating thing is that it states:
"We pledge to work to protect the life of every human being from conception to its natural end and we refuse to comply with any directive that compels us to participate in or facilitate abortion, embryo-destructive research, assisted suicide, euthanasia, or any other act that involves intentionally taking innocent human life."
Clearly this is aimed at abortion/ euthanasia. But the pledge does seem pretty unequivocal if taken to its logical conclusion. It is hard to see how protecting "the life of every human being" and opposing "any other act that involves intentionally taking innocent human life" could for example square with any support for the invasions of Iraq or Afghanistan, or for that matter the replacement of Trident.
The signatories don't seem to have spotted this. Indeed, the statement doesn't mention peacemaking in any shape or form as a Christian pursuit (despite its absolute centrality to the Christian faith and the Bible). Nor does it mention Iraq, Afghanistan or Trident even though these will also be relevant issues to this election. Contrast this for example with the integrated approach of Church leaders in Scotland today who link the message of Easter with a call relating to Trident .
What it does show is the extent to which those putting the Westminster Declaration together are dualistic in their thinking, selective in their focus, and ignore some of the most central aspects of their faith that have something to say to the world around them - despite their claim to be 'representing' Christianity.
In their zeal to combat the 'marginalisation' of Christianity, they are actually doing a great deal to marginalise the faith themselves.