The man could have been a Pyro!
In giving counsel how to inflame the heart with a love for truth, William Gurnall wrote this:
Too often, we've seen men who begin more or less Biblically orthodox, who then drift further and further from the safe haven of God's Word. William Gurnall suggests one reason why.
Likeness is the ground of love. A carnal heart cannot like truth, because it is not like to truth. Such a one may love truth, as he did Alexander, Regem non Alexandrum; ‘the king, not the person that was king:’ truth in its honour and dignity, when it can prefer him, but not naked truth itself.
How is it possible an earthly soul should love truth that is heavenly? An unholy heart, truth that is pure? O it is sad indeed, when men’s tenets and principles in their understandings do clash, and fight with the principles of their hearts and affections!
When men have orthodox judgment, and heterodox hearts, there must needs be little love to truth, because the judgment and will are so unequally yoked; truth in the conscience reproving and threatening lust in the heart, and that again controlling truth in the conscience. Thus, like a scolding couple, they may a while dwell together; but taking no content in one another, the wretch is easily persuaded to give truth a bill of divorce at last, and send her away, as Ahasuerus did Vashti, that he may espouse other principles, which will suit better with his corrupt heart, and not cross him in the way he is in.
This, this I am persuaded hath parted many and truth in these licentious days. They could not sin peaceably while they kept their judgments sound; truth ever and anon would be chiding them; and therefore, to match their judgments with their hearts, they have taken up principles suitable to their lusts. But, soul, if truth had such a power upon thee, to transform thee by the renewing of thy mind into its own likeness, that as the scion turns the stock into its own nature, so truth hath assimilated thee, and made thee bear fruit like itself, thou art the person that will never part with truth; before thou canst do this, thou must part with that new nature, which by it the Spirit of God hath begot in thee. There is now such a near union betwixt thee and truth, or rather thee and Christ, as can never be broke.
We see what a mighty power there goes along with God’s ordinance of marriage, that two persons, who possibly a month before never knew one another, yet their affections once knit by love, and their persons made one by marriage, they can now leave friends and parents for to enjoy each other; such a mighty power, and much greater, goes along with this mystical marriage between the soul and Christ, the soul and truth, that the same person, who, before conversion, would not have ventured the loss of a penny for Christ, or his truth, yet now, knit to Christ and his truth by a secret work of the Spirit new forming him into the likeness thereof, he can bid adieu to the world, life, and all, for these.
As that martyr told him that asked whether he did not love his wife and children, and was not loth to part with them, ‘Yes,’ saith he, ‘I love them so dearly, that I would not part with any of them for all that the Duke of Brunswick is worth,’ whose subject he was; ‘but for Christ’s sake and his truth, farewell to them all.’
[William Gurnall and John Campbell, The Christian in Complete Armour (London: Thomas Tegg, 1845), 222–223. Broken into paragraphs]