John Ringo

When Marine Private Oliver Chadwick Gardenier is killed in the Marine barracks bombing in Beirut, somebody who might be Saint Peter gives him a choice: Go to Heaven or return to Earth. The Boss has a mission for him. He's a Marine: he chooses the mission. Eventually, it appears that God's will is for Chad to join a group called "Monster Hunters International" and protect people from things that go bump in the night. From there, things trend downhill....