Thinking in Christ — Issue 1

A Mind Renewed to Test All Things

"Test all things, and hold firmly that which is good." (1 Thess 5:21)

This is the work of a mind: not to swallow every word that comes to it, and not to reject every word out of pride, but to test, and to hold fast to what is good. The simple man believes everything; the prudent man carefully considers his ways (Prov 14:15). That contrast is the definition of clear thinking. A mind that believes everything is not open. It is unguarded. A mind that considers its ways is not suspicious. It is awake.

Therefore the question is not whether a mind will be shaped. Every mind is shaped by something. The question is what shapes it, and to whom it belongs.

For apart from Christ, the mind is not a clean slate waiting for facts. It is darkened. Scripture describes those apart from Christ as "being darkened in their understanding, alienated from the life of God, because of the ignorance that is in them, because of the hardening of their hearts" (Eph 4:18). Darkness here is not a lack of information. It is a condition of the understanding itself. A darkened mind can gather facts all day and still miss the truth, because the instrument of judgment is itself disordered.

Because of this, no mind is neutral. There is no thinking that stands nowhere, beholden to no master, judging all things from an untouched height. The mind serves sin or it serves God (Rom 6:16). It is conformed to this age or it is transformed. "Don't be conformed to this world, but be transformed by the renewing of your mind, so that you may prove what is the good, well-pleasing, and perfect will of God" (Rom 12:2). Conformation is the default. The age presses its mold onto every mind left to itself: its slogans, its fears, its definitions of good and evil, its hurry. Renewal is the interruption of that molding, and renewal is not self-performed. It is God's work in the mind, by His Word and Spirit.

Yet the same Scripture that denies neutrality commands testing. The command to test all things is given to minds that must be renewed, not to minds that are already trustworthy. This is why the heart cannot be the judge of the heart. "The heart is deceitful above all things, and it is exceedingly corrupt: who can know it?" (Jer 17:9). A deceitful heart will call its own desires evidence and its own habits wisdom. It will bless whatever flatters it and condemn whatever crosses it. So the test cannot be, "Does this feel true to me?" The test must stand outside the self. The Word of God is that outside standard: it judges the thoughts of the heart rather than being judged by them (Heb 4:12). By long use under that Word, the senses are trained to discern good and evil (Heb 5:14). Discernment is not a talent a person is born with. It is a discipline formed by submission.

This is why clear thinking matters, and why it matters everywhere rather than only in a classroom. The flood does not stop at the study door. Claims arrive by the thousand: in the home, where a word can wound or heal; in the workplace, where a decision can serve or exploit; in the public square, where a slogan can carry a crowd; in the marketplace, where a promise can hide a snare. The mind that has never learned to test is carried about, as Scripture warns, "tossed back and forth and carried about with every wind of doctrine, by the trickery of men, in craftiness, after the wiles of error" (Eph 4:14). Trickery succeeds precisely because it does not announce itself as trickery. It arrives as confidence, as consensus, as urgency, as compassion. The untested mind mistakes the loudest voice for the truest one.

Likewise, evidence has its place, but it is not the foundation. A witness can corroborate; it cannot create the ground on which faith stands. "If we receive the witness of men, the witness of God is greater; for this is God's testimony which he has testified concerning his Son" (1 John 5:9). Human testimony is received, and received testimony can confirm and clarify. But faith does not rest on the accumulation of proofs, as though God must wait for the evidence to reach a quorum before He may be believed. God's testimony stands first, and it stands on His own authority. Evidence that agrees with it is welcome corroboration. Evidence wielded as a replacement for it is a rival authority, and it will fail the mind that leans on it, because every human witness is partial and every human argument can be turned.

At the same time, this testing is not cold detachment. The mind that tests all things is not the mind that trusts nothing. It holds firmly to what is good. Testing without holding fast is only another form of drift: the perpetual skeptic keeps every question open and never stands anywhere. Holding fast without testing is only another form of captivity: the credulous mind stands wherever it was last placed. The command joins the two acts. Test, and then hold. Let go of what fails the Word, and grip what the Word confirms, even when the age calls it foolish.

Thus the whole matter comes to Christ. Apart from Him, testing has no true standard and no true end, because the mind tests by its own darkened light and calls its own verdict truth. In Him, the mind is given both its standard and its renewal. "But you did not learn Christ that way" (Eph 4:20). Learning Christ is not the acquisition of one more opinion among opinions. It is the remaking of the learner: "that you be renewed in the spirit of your mind" (Eph 4:23). And the renewed mind does not roam free of all authority. It brings its thoughts somewhere. The warfare of the renewed mind is "throwing down imaginations and every high thing that is exalted against the knowledge of God, and bringing every thought into captivity to the obedience of Christ" (2 Cor 10:5). Captivity to Christ is the only captivity that frees, because Christ is the truth itself (John 14:6), and the truth He speaks makes free those who were slaves to sin (John 8:32). The mind that will not be captive to Him will be captive to something lesser: to a teacher, a party, a fashion, a fear, a flattering philosophy that takes minds captive by empty deceit (Col 2:8).

So here is the definition, stated plainly. To think clearly is to have a mind renewed by God, testing every claim by His Word, refusing both credulity and cynicism, holding fast to what is good, and bringing every thought into obedience to Christ. It is not independence. Independence from God is the fall, not a skill. It is not neutrality. No mind is neutral. It is not cleverness. Cleverness can defend any cause, including a false one. It is dependence made disciplined: a mind that knows its own deceit, distrusts its own first verdict, submits to a Word outside itself, and therefore can be trusted, by grace, to judge well in the home, in the work, in the city, and in the marketplace.

The testimony that grounds all of this is simple, and it is the ground on which this whole series stands: "The testimony is this, that God gave to us eternal life, and this life is in his Son" (1 John 5:11). A mind that has received that testimony has received more than a conclusion. It has received a Lord. Test all things, then. And hold firmly to what is good, for the good is not an abstraction. The good is Christ, and the mind renewed by Him is the mind finally fit to think.