Another Michael A. Smith freebie - The Inheritors (The Jeremiah Trilogy).
Jeremiah the Terrorist Prophet has developed a genetically engineered, virulent variation of the flu virus, and found the perfect delivery vehicle--the hundreds of millions of migratory birds that circle the globe each year. His followers, including dissident military units and sympathizers from all around the world, have received a vaccine and stand ready to reestablish Eden after the "earthly garden" is weeded. God ordained the apocalypse in his Revelation to Jeremiah. The Prophet tries to recruit his two adult sons to the effort, but they have strong ties to the terrorist's archenemies, Steve Wallace and Laura Delaney. The action is fast and furious in this conclusion to the Jeremiah Trilogy, a ripped-from-the-headlines look at all aspects of terrorism in our time.