Something to Shout About by Sheila Jacobs and published by Christian Focus Publications.
Jane and Heather are reunited and decide to try and re-invigorate Heather's church, which has fallen on hard times. They arrange a 'Save our Church' campaign along with the help of a friend's brother who happens to be an environmental campaigner. The campaign is a disaster and Jane and Heather realise that they didn't pray to God about the situation and cared more about what they wanted than about what God had planned for the situation. Jane and Heather also learn that you can worship God anywhere and that the church is not a building but it is a group of people worshipping God together.