That would make the Jesus who rains death and destruction his agent Metatron.
The Tribulation Force is a group of underground Cultists who conspire to see The End of the World as We Know It brought about by an Eldritch Abomination. This will involve a great purge as all those who do not supplicate before their God of Evil are subjected to mortal tortures before being cast into a lake of Hell-Fire to burn for eternity. This is justified by a Blue-and-Orange Morality of a deity who loves mortals but punishes them if not loved in turn in a Why Did You Make Me Hit You? kind of way.
- From a Certain Point of View, this WMG is actually canon.
The Underground Zealot trilogy is a prequel to Left Behind
This one is actually Word of God as per Jerry Jenkins' Facebook page. See here: http://emlia.org/pmwiki/pub/web/Tripocalypse.UZLBLink.html