Published in the mid-1980s, this bestselling novel reflects the contemporary culture wars. It represents the assuredness of an ascendant Christian Right, empowered by the sympathetic administration of President Ronald Reagan, to assert its views as truth (while at the same time presenting itself as under attack and embattled).

For, while This Present Darkness is a novel, it is also a polemic, defined as a strong attack on certain people or ideas. For example, Orwell's 1984 is a polemic in its unwavering attack on totalitarianism, censorship, and groupthink.

This Present Darkness is an unequivocal assault on what Peretti considers the deep dangers of a "New Age" society. Himself an Assembly of God (an evangelical Christian denomination) pastor, he presents the conservative theology of his church as the "Truth" and as the Christian way.

This leads to an "us" versus "them" mentality. Characters are either with the Truth or against it (whether they realize it or not). Taking a stand is perhaps the most important value this novel espouses. According to Peretti, the New Age is dangerous and seductive precisely because it promotes liberal values such as tolerance and the belief in the universal goodness of all people.

The novel puts forth that these values, which look desirable and reasonable on the surface, are the way the Devil gradually chips away at people's faith in Jesus Christ as the one and only narrow path to salvation, replacing it with a devilish Universalist vision. What looks good is in fact evil—and this is how, according to the novel, evil works: Satan's minions come disguised as angels of light.

As many have observed, this mentality leads the defense of Christianity into uncomfortably unchristian positions. For example, a big red flag in the novel is that a character, a New Age demon-possessed individual, actually cites a Bible verse—Matthew 7:1, "Judge not, that ye be not judged." This verse, spoken by Jesus, is violently rejected in this novel.

To give the novel its due, one could argue that the verse is twisted and misused by its New Age advocates because it does not mean what it seems to mean; however, this too is ironic in a novel that leans heavily into Biblical literalism, which asserts emphatically that the Bible means exactly what it seems on the surface to mean.

Judgment is at the core of the novel: salvation comes as people are able to rightly discern the angelic from the demonic. In another move that some have criticized an antithetical to Christianity, the novel is more concerned with the destruction of the non-believer than loving conversion: the Satanic pollution vying for the minds of the believers must be confronted in literal battle, destroyed, and wiped out.

This is strong polemic, but unlike 1984, it is based on a black and white, "evil or good" conflict. But it is perhaps this very lack of ambiguity—the novel tells the reader very clearly what to think rather than encouraging independent thought—that is the key to its popularly.