Hundreds of thousands of Christians will unite in prayer later this month in the most ambitious evangelism project in a generation.
The Archbishop of Canterbury is calling on believers of all denominations to back his 'Thy Kingdom Come' initiative, aimed at bringing together sparking a wave of prayer around the world.
'It's not a Church of England thing, it's not an Anglican thing, it's a Christian thing,' said Justin Welby.
'Jesus prayed at the Last Supper that we, those who follow him, might "be one that the world might believe". We are invited to make a lasting difference in our nations and in our world, by responding to his call to find a deep unity of purpose in prayer.'
He added: 'In these times of transformation across Europe, mass migration and war, it has never been more important to pray in whatever way we can. To be transformed as individuals and as communities so that we deepen our relationship with God and work together towards peace.'
The project, now in its second year, saw more than 100,000 people join the Archbishops of Canterbury and York for 10 days of prayer in 2016 between the Christian festivals of Ascension – which celebrates Jesus departing to heaven after his resurrection, and Pentecost – which celebratesthe Holy Spirit falling on Jesus' disciples.
Many more are expected to join this year with the initiative reaching Catholics, Pentecostals, Baptists and free evangelicals as well as Anglicans.
Stretching right around the world churches are organising firework celebrations, street parties, prayer walks, candlelit services and prayer tepees.
In the UK the BBC will live broadcast a service on Pentecost Sunday featuring Welby alongside the charismatic worship leaders Matt Redman and Tim Hughes as well as Liz Adekunle, archdeacon of Hackney.
Emma Buchan, who heads up the project, says the response has been 'overwhelming'.
She says: 'We've heard from churches across the world, including different denominations and traditions, who have all pledged to get involved from South Africa to Canada and from the Brazil to Hong Kong. Each place is organising the time in their own way, for example in Hong Kong they are planning big celebrations in the cathedrals and establishing a network of "prayer warriors".'