It'll now be led by Mike Andrea who will serve as CEO.
24-7 Prayer is an international, interdenominational movement of prayer.
It equips people to pray in churches, schools, nightclubs and various other places.
Announcing the move on Facebook, Greig said: "Sammy (wife) and I are entering a new season having celebrated our 25th wedding anniversary while our sons turned 21 and 18, I turned 50, and 24-7 turned 20 all in the last year. We sense that this is meant to be a time of jubilee!
"Of course, we will continue to bring leadership to the 24-7 movement - speaking, writing and offering hospitality, mentoring and convening key leaders, supporting the worldwide family of 24-7 communities, shaping culture and vision at a high level. We will also continue to lead and be deeply rooted in our Christian family at Emmaus Rd Church, serve on the Wildfires Festival team and Sammy will continue to train as a Counsellor. There's plenty to do!
"Meanwhile, the church and the movement continue to grow which means that the pressures on my schedule have been increasing unsustainably for quite some time. Candidly, I need to slow down without slowing the movement down. This means relinquishing position, power and control - something that leaders aren't always very good at - but by God's grace we find ourselves simply overwhelmed with joy."
Greig will continue to serve the organisation alongside other work through speaking, writing and mentoring.
The decision to appoint Mike Andrea as his successor has been approved by the senior leadership teams that serve the 24-7 movement.
After being saved from a life in violent gangs and crime, he's devoted his life to the Church serving as pastor to Global Generation Church in Thanet and was recently honoured by Her Majesty the Queen for his work in community transformation.
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