I read Soon by Jerry Jenkins a few years back. This book and the Underground Zealot series (Silenced and Shadowed) is excellent! If you enjoyed the Left Behind series, you will enjoy this series.
Book Description from the publisher:
Paul Stepola, an agent working for the National Peacekeeping Organization (NPO), has been assigned to enforce compliance with the world government's prohibition on religion. Paul relishes his job and is good at it. He is determined to expose underground religion--flush it out, expose it, and kill it--until his life is turned upside down and he is forced to look at life in a different way. As Paul begins to unravel the truth about what he has found, events taking place around the world start to make sense. Something big is coming--something that can't be stopped. And it is coming soon.