The Dutch Reformed thinker and poet Willem Bilderdijk recalls in a letter to a friend in 1822 what his former teacher once said: “When examining the truth of Christianity, you must be as much a heathen as a Christian in order to judge freely.” This troubled Bilderdijk for the simple reasons that it failed to honor Christ, first and foremost, and to account for the antithesis between believers and unbelievers. He writes,
This beautiful sounding precept, which then dismayed me, is indeed of the evil one and seduces whoever accepts it: because it contains  unfaithfulness to God and the Savior to whom we are sanctified in baptism and  a fundamental apostacy. — No, we must cling with all of our soul to the Savior, value and hold fast with our heart the Grace that has called us, and fight Unbelief in God’s might and not under the Banner of Reason.
By the “Banner of Reason,” Bilderdijk has in mind not reason in itself but reason understood specifically as an autonomous source of knowledge that can function independent of God and his revelation. And so, he recognized that if believer and unbeliever alike fight under the Banner of Reason, then (autonomous) reason must triumph in the end. For the believer to raise the Banner of Reason is for him to desert his Commander; it is “a fundamental apostacy.” Bilderdijk continues,
Then it will not be difficult to see the falsity of the feigned refutations [of God]. They gleam in the eye, but one must not let himself be moved into the standpoint of those who cannot see the light of truth from their standpoint. I must not close my eyes with the blind man in order to debate with him whether or not the sun shines. If someone denies that I have a good library or a well-stocked cellar, I must not shut up the room or cellar, but bring him in there with me. Or, if he is too crippled to go up and down the stairs with me, then let him talk, and I will enjoy my privilege in gratitude toward God who gives me these refreshments for soul and body. — If I can refute the unfortunate by the communication from there, so much the better; but to set aside my possession and consciousness of it in order to refute his arguments from those arguments themselves would be folly.
Believers and unbelievers view all things from different “standpoints” or “worldviews,” as Bilderdijk speaks of elsewhere. For the believer to adopt the unbeliever’s mode and position of seeing in order to debate with him would be as foolish as someone debating a blind person as to whether or not the sun is shining by closing his own eyes. He deprives himself of that which alone can recognize the thing in question. The Christian must not set aside his “possession,” graciously given to him by God, in order to refute the arguments of unbelievers by the unbeliever’s own arguments. Is it not telling that it is typically those fighting for the faith who are lured under the “Banner of Reason” and not the other way around? Neutrality is a myth.
Bilderdijk realized that someone could object to this as simply begging the question (petitio principii). He responds,
All feeling is petitio principii and cannot be disproved or proved by reason. And so it is with the Feeling of Grace [Genadegevoel], that is, with Religion. It is of God, it is the working of God’s Spirit in our heart, and the mind must receive it from our heart. Without this, intellectual Religion is a mere Historical or Philosophical view, nothing more, and does not prove Christianity but Paganism.
This Romantic version of “faith seeking understanding” is basic to the Reformed theology that Bilderdijk sought to defend and promote. A test case is the believer’s reception of the Bible’s sixty-six books as holy and canonical and his undoubted belief in all things contained in them. The Belgic Confession, which Bilderdijk affirmed, states that the believer receives these books and believes all things in them “above all because the Holy Spirit testifies in our hearts that they are from God” (article 5). As Bilderdijk said, “[I]t is the working of God’s Spirit in our heart, and the mind must receive it from our heart.” The mind is not independent, but dependent upon the heart and the Spirit.
In apologetics, the believer must not set aside “his possession and his consciousness of it” in order to argue from the unbeliever’s resources. Rather, “we must cling with all of our soul to the Savior, value and hold fast with our heart the Grace that has called us, and fight Unbelief in God’s might and not under the Banner of Reason.”
And so Bilderdijk did. As Herman Bavinck writes of him, “Against the Revolution, he raised the banner of the Gospel.”
 Willem Bilderdijk, “Aan Mr. Samuel Iperuszoon Wiselius,” in Brieven 3 (Amsterdam, 1837). All quotations in this article are taken from here. All translations are my own.
 Herman Bavinck, Bilderdijk als denker en dichter (Kampen: J. H. Kok, 1906), 216, my translation.