Worshippers are being asked to "put their faith into action" by using electricity from solar or wind energy, in a mass bid to tackle climate change.
Campaigners from the charities Christian Aid and Tearfund claim that Christians are deeply concerned about climate change, and want "warm actions not just warm words" to halt its progress.
For 'The Big Church Switch' starting on Wednesday, they hope contact at least 150,000 Christians of different denominations to encourage them to switch their provider or tariff to renewables.
Churches are being encouraged to 'lead the way' in renewables
Leading bishops are backing the campaign which calls on the faithful to show they "love their neighbours" and care for creation.
Churches are also being asked to switch to using only green energy, and the Lutheran Church and Quakers in Britain have already switched to 100% renewable tariffs.
The Big Church Switch is calling itself a "new initiative responding to the Christian community’s concern around climate change". It will offer a website with information on how to switch tariff easily from Ash Wednesday, 10 February, which marks the first day of Lent.
Organisers hope to send a message to the government that churches are prepared to "lead the way" in using renewables instead of fossils fuels, whose burning releases gases that cause climate change.
Churches will be encouraged to invite local politicians to services and tell them about the importance of green energy and why the government must do more to reduce CO2 emissions.
'Switching is a great way for Christians to love our neighbours'
Nicholas Holtam, the Bishop of Salisbury, who leads on environmental issues for the Church of England, said it was a "simple, practical good idea".
"If Lent is about renewing our lives in response to the love of God here is a way to follow," he said. "You can do it, and so will I.”
Ben Niblett, Tearfund Senior Campaigner said: "The UK church has a vital role in overcoming poverty and inequality in a way which doesn’t cost the earth and lasts for generations to come. Switching is a great way for Christians to love our neighbours and show the government we want more action on climate change, like investment in clean, renewable energy.
'’Christians care about our neighbours in the UK and around the world being hit by climate change - we're seeing more floods, more droughts, and more people going hungry - so we think this will strike a chord.'’
The campaign is backed by figures including the Bishop of Liverpool, Paul Bayes; the Bishop of Manchester, David Walker; the Bishop of Guildford, Andrew Watson and the Bishop of Truro, Tim Thornton.
Climate change is a key concern for Christians, the campaign claims
Laura Taylor, Christian Aid’s Head of Advocacy, said: “The congregation at my own local church, Epsom Baptist Church, wanted warm actions not just warm words, so we are going to put our faith into action by switching as part of this movement. I encourage every church to join the campaign.”
The project also hopes to use the buying power and "combined consumer force" of thousands of Christians to leverage green deals with energy providers.
A spokesperson for Christian Aid told The Huffington Post UK: "Christian Aid and Tearfund will communicate with its supporters through mailings and emails over Lent. This is never an exact science, but we hope that together we can reach over 150,000 Christians who will take this campaign up through their churches."
It also hopes to reach the faithful and church leaders through parish newsletters, as well as climate change charities. "We’ve already had a number of dioceses make requests for our materials," the spokesperson added.
David Walker, Bishop of Manchester, supports the campaign
Churches that have switched to green energy could be given special posters to display as "a badge of achievement" and the campaign hopes to keep a record the number of churches using green energy, to show politicians the "growing commitment of the church to source its energy in a way that cares for creation."