A British former gang member will appear alongside Pope Benedict XVI during the World Youth Day evening vigil on July 19 to describe how God dramatically changed his life.

John Pridmore, 44, was once an enforcer in the London underworld whose life involved stabbings, guns, major drug deals and vicious gangs. After he nearly killed a man in a 1991 fight outside a bar, his life changed radically. He has since become a public speaker, having addressed an estimated one million people in various parishes, schools and prisons.

His book, “From Gangland to Promised Land,” has become a best seller.

Pridmore will also appear on stage at the “Receive the Power Live” concert on Friday, July 18 at Barangaroo in Sydney Harbor. He will be joined by singer-songwriter Darlene Zschech and Hillsong United, Matt Maher and his Band and other artists.

The Barangaroo venue has been specially constructed for World Youth Day. It has a capacity for 150,000 people and those unable to attend the concert will be able to watch it on large TV screens around Sydney.