This post was first published during April 2014. –ed.

We saw last time that Paul affirmed the Bible as the only reliable criterion by which believers in this age can evaluate messages claiming to be truth from God. That testing of truth Paul calls for is not merely an academic exercise. It demands an active, twofold response.

First there is a positive response to whatever is good: “Hold fast to that which is good” (1 Thessalonians 5:21). This is an echo of Romans 12:9: “Abhor what is evil; cling to what is good.” The expressions “hold fast” and “cling to” speak of jealously safeguarding the truth.

Paul is calling for the same careful watchfulness he demanded of Timothy every time he wrote him: “O Timothy, guard what has been entrusted to you” (1 Timothy 6:20); and “Retain the standard of sound words which you have heard from me. . . . Guard, through the Holy Spirit who dwells in us, the treasure which has been entrusted to you” (2 Timothy 1:13–14).

In other words, the truth is given to our custody, and we are charged with guarding it against every possible threat. It’s a militant, defensive, protective stance against anything that undermines the truth or does violence to it in any way. We must hold the truth securely, defend it zealously, and preserve it from all threats. To placate the enemies of truth or lower our guard is to violate this command.

Paul’s exhortation to “hold fast” also carries the idea of embracing something. It goes beyond basic assent to “that which is good” and speaks of loving the truth wholeheartedly. Those who are truly discerning are passionately committed to sound doctrine, to truth, and to all that is inspired by God.

Every true Christian has this quality to some degree. Paul even defined salvation as “the love of the truth” (2 Thessalonians 2:10), and he told the Corinthians they proved their salvation by holding fast to the gospel he had delivered (1 Corinthians 15:2). Those who utterly fail to hold fast to the saving message are those who have “believed in vain”; that is, their faith was empty to begin with. The apostle John said something similar: “They went out from us, but they were not really of us; for if they had been of us, they would have remained with us; but they went out, so that it would be shown that they all are not of us” (1 John 2:19). All true believers hold fast to the gospel.

Paul was urging the Thessalonians to nurture and cultivate their love for truth, to let it rule their thinking. He wanted them to foster a conscious commitment to all truth; a faithfulness to sound doctrine; a pattern of holding fast to all that is good.

The attitude Paul calls for is incompatible with the suggestion that we should lay doctrine aside for the sake of unity. It cannot be reconciled with the opinion that hard truths should be downplayed to make God’s Word more palatable for unbelievers. It is contrary to the notion that personal experience takes precedence over objective truth. God has given us His truth objectively in His Word. It is a treasure that we should protect at all costs.

This is the opposite of reckless faith. Paul leaves no room for rote tradition. He makes no place for a blind, irrational faith that refuses to consider the authenticity of its object and just accepts at face value everything that claims to be true. He rules out the kind of “faith” that is driven by feelings, emotion, and the human imagination. Instead, we are to identify “that which is good” by examining everything carefully, objectively, rationally—using Scripture as our standard.

No human teacher, no personal experience, no strong feeling is exempt from this objective test. Jay Adams writes, “If inspired prophecies in the apostolic age had to be subjected to testing . . . then surely the teachings of men today should also be put to the test.” Indeed, if the words of prophets in apostolic times needed to be examined and evaluated, then surely we ought to subject the words of self-proclaimed “prophets” and preachers today to even more intense scrutiny in the bright light of the completed New Testament. The same is true of every subjective experience and every emotion. Experience and feelings—no matter how powerful—do not determine what is true. Rather, those things themselves must be subjected to the test.

“That which is good” is truth that accords with God’s Word. The word “good” is kalos, meaning something that is inherently good. It isn’t just something that is fair to look at, lovely or beautiful in appearance. This speaks of something good in itself—genuine, true, noble, right, and good. In other words, “that which is good” does not refer to that which is entertaining. It does not refer to that which garners accolades from the world. It does not refer to that which is satisfying to the flesh. It refers to that which is good, true, accurate, authentic, dependable—that which is in agreement with the infallible Word of God.

When you find such truth, embrace it and guard it like a treasure.

(Adapted from Reckless Faith.)