The Rise of the Fallen (The Angelic Wars Book 2)

Thirteen year old Christopher Wright was a kid from the streets. When word got out that he could heal with a touch, a gang known as Talon tried to recruit him. When Chris turned them down, the gang attempted to take him by force. On the run, Chris met Judge Hawkes, the head of a mysterious group known as the Angelic Dominion. The judge informed the skeptical teen that he was one of a group of young people who had been born with the souls of angels. They had been sent to Earth to stop the forces of Hell from bringing about the Apocalypse.
To escape Talon, Chris reluctantly accompanied the judge back to his home to learn that he had, in fact, been telling the truth. He met others like himself and discovered that he wasn't simply the bearer of an angel's soul. His was the soul of one of the very first archangels: Sariel, brother of Michael and Lucifer.
Doomed to dwell in Purgatory and guard the Gates of Heaven, Sariel is determined to stop his Fallen brother's forces here on Earth before they can destroy humanity and march on Heaven itself.