Most Rev Michael Curry, presiding bishop of The Episcopal Church in the US, is joining a global call to pray today.
The Archbishop of Canterbury's Thy Kingdom Come initiative launches today, aiming to spark a wave of unity across churches for 10 days of prayer between the Christian festivals of Ascension and Pentecost.
Curry, who leads the TEC which is currently experiencing 'consequences' for its acceptance of gay marriage and has been barred from full participation in the Anglican Communion affairs, opens a series of videos calling on Christians to join the movement.
'God came among us in the person of Jesus of Nazereth to change the world,' he says in the clip.
'Prayer actually does change things. We may not always know how, we may not always know the details, we may not always see the result or the end product, but prayer changes things.
'Prayers alters the chemistry of the moment, changes the equation of history and life.'
He adds: 'So if you want things to stay the same don't bother to pray.
'But if you want to pray and you want the world to change, pray.'
The initiative is Welby's project and he says he has never felt God speak so clearly as on this.
'It's not a Church of England thing, it's not an Anglican thing, it's a Christian thing,' he has said.
'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 said: '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.'
