It’s sort of like the believer and the unbeliever. The unbeliever thinks the believer is wasting his time. The believer can simply counter with all the positive aspects of being a believer but the believer really has nothing to lose if he is wrong. The unbeliever on the other hand most certainly does.
Let's see if I understand the author correctly.
As a thief veils his presence from those he wishes to steal from, so the Lord has veiled the doctrine of the Pre-Tribulation coming for His church.
The author admits the doctrine in a novelty. That is a very Weird statement he makes, BTW.
Anyway
Of course there are many honest, born-again believers in Christ do not agree with the Pre-Trib doctrine. Those believers are not seeking to devour those of us who do. I have to seriously question the motivation of those who focus the majority of their “work for the Lord” in vitriolic attacks launched against the hearts of those who hold to the Pre-Trib Rapture doctrine. Such attacks are an attribute of Satan, not of Christ.
Anyway, per the author it's OK not to not believe "the Pre-Trib doctrine" (a metonymy, probably, for the whole mass of bog standard dispensational teaching), but if one says anything, one is a spawn of Satan.
It seems that he can't quite bring himself to call them unbelievers, but he wants to.
1 Corinthians 2:13 Which things also we speak, not in the words which man's wisdom teacheth, but which the Holy Ghost teacheth; comparing spiritual things with spiritual.
14 But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned.
15 But he that is spiritual judgeth all things, yet he himself is judged of no man.
16 For who hath known the mind of the Lord, that he may instruct him? but we have the mind of Christ.