Based upon the best-selling religious fiction novels about the aftermath of The Rapture (the End Times event when God takes the Christians to Heaven and leaves everyone else to their fates on Earth), Left Behind: Eternal Forces is not the real time strategy game that most people expected it to be.
It is not about gunning down non-Christians in a burst of theocratic wish fulfillment - so really, few folks other than that dude who sued the government over the "In God We Trust" on US money are likely to be offended. It is also not the effective missionary tool that its creators may have hoped to create - Left Behind compromises much of its nobility with commercialism, and preaches to the converted more than the curious.
Whether or not you agree with its spiritual message, Left Behind's game design is not on the side of the angels. It has no single player skirmish mode, so you are left with a story-based campaign that opens with a dozen nearly identical quests. Your goal is to recruit and keep converts to your cause, non-violently if possible (often through playing spiritual music) but sometimes with tanks and guns. The campaign only tells one side of the story, so you won't get to control the forces of evil unless you go online for multiplayer action. But honestly, this isn't The Lord of the Rings, with angry trees and flaming balrogs and nazgul - these participants are all people, so both factions are pretty much identical from a gameplay perspective, anyway.
Not only are there too few game modes, but the gameplay itself is rugged. Left Behind has too many technical problems to recommend it to serious strategy gamers of any spiritual stripe. The units you put in charge of recruiting can't find their way around. They'll balk at crossing an empty street to find a convert, and lampposts prove to be major navigational hazards.