What does it mean to hold fast to that which is good (1 Thessalonians 5:21)?

“Hold fast that which is good”. Having proved what we hear we are to hold fast the good. The tendency, too often, is to remember what is unprofitable, and to let go the good.

But on the other hand we are not to accept anything that is said without subjecting it to the test of the Word of God. We are to "prove all things." However, young in the faith, this was the personal responsibility of every saint. Nothing was to be taken for granted or taken merely on the word of another; Scripture was their one real authority. And what is good we are to hold fast, allowing nothing to slip of the precious truth of God. This too was essential if they were to "avoid every form of evil" U.N. Darby). For evil will assume most attractive and deceiving forms just as readily as more gross forms, and only the heart holding fast what is good will be protected.

Verses 19 to 22 refer more to matters which concerned the assembly of God's saints, where the Spirit of God operated and made known the mind of God. There, in those early days, He was accustomed sometimes to speak and act in supernatural ways, — see Acts 13:2; 1 Corinthians 12:7-11; 1 Timothy 4:1. He also, in a more general way, made His voice heard in the ministry of the prophets, as contemplated in 1 Corinthians 14. The Thessalonians were not to attempt to regulate the action of the Spirit in the assembly or they would quench His action. It is not for us to control the Spirit, but for Him to control us. Prophesyings were to be given their due place of importance and yet, seeing that such a thing as prophecy of a spurious sort was not unknown, everything they heard was to be "proved;" i.e., tested, for though they had not as yet the written New Testament, they had the Old Testament and the verbal instructions of the apostle. Having tested what they heard they were to "hold fast" all that was good and "abstain from" or "hold aloof from" evil in all its forms.

Such were the apostle's exhortations to guide their walk with others. As regards their personal state, joy, prayer, thanksgiving in all things, these should be their characteristics. With respect to the public actings of the Spirit in their midst, the apostle's exhortations to these simple and happy Christians were equally brief. They were not to hinder the action of the Spirit in their midst (for this is the meaning of quenching the Spirit); nor to despise that which He might say to them, even by the mouth of the most simple, if He were pleased to use it. Being spiritual, they could judge all things. They were therefore not to receive everything that presented itself, even in the name of the Spirit, but to prove all things. They were to hold fast that which was good; those who by faith have received the truth of the word do not waver. One is not ever learning the truth of that which one has learnt from God. As to evil, they were to abstain from it in all its forms.

But there is responsibility upon another side; and so the apostle continues: "but prove all things, hold fast the right." Not everything that assumes divine authority for itself can be received as such. The Word must for us try everything, — the written communication be held superior to the prophet's voice: for here, alas, man's frailty and fallibility are to be remembered; while, moreover, we are to take heed, because "many false prophets are gone out into the world." Thus the Christian as a possessor of the truth is held to his responsibility to know and to maintain the truth. He cannot be deceived, except as he permits himself to be deceived; for he is not a child of darkness, but of the light: he has but to maintain his place as such, and be subject to that Spirit which has come to be in him the Witness for his absent Lord. To Him the various forms of evil, however specious and alluring, are known fully. "The wise" (with that fear of God which is the beginning of wisdom) — "the wise shall understand." Apart from such fear, which is not always to be found, alas, in the true Christian, we walk exposed to the enemy. Satan may assume the form of an angel of light; but we are not to be ignorant of his devices. Yet the whole armor of God is needed, that we may be able to stand against the wiles of the devil.

We are not to despise prophesyings, nor are we to receive everything that presents itself, even if professedly given by the Spirit, but to "prove all things," and "hold fast that which is good" (1 Thess. 5:20-21). If the truth ministered is proved by Scripture, and held in faith with God, we shall not waver in our convictions with every wind of doctrine. As J. N. D. has remarked, "One is not ever learning the truth of that which we have learnt with God." Again he has remarked, "If I do not believe the Word till it be sanctioned by someone else, I do not believe it at all; it is the sanction I believe." When, however, the teacher is exalted into a false position, and we accept what he says because he says it, without putting it to the test of the Word, we are in danger of being led into perversions of the truth, and losing the truth we once professed to hold.

"But if there be no interpreter, let him keep silence in the church; and let him speak to himself, and to God" (ver. 28). If what he has got to say cannot be made understandable to others, it is of no use — it is excluded. "Let the prophets speak two or three, and let the others judge" (ver. 29). Not to permit this when the Assembly is gathered together is to quench the Spirit. That is as clear as daylight from another scripture, where the apostle says, "Quench not the Spirit. Despise not prophesyings. Prove all things; hold fast that which is good" (1 Thess. 5:20-21). To despise or hinder the freedom of the prophets is to quench the Spirit. Solemn reflection. I could not, and would not, recognise anything as the Assembly of God where this liberty of the Spirit of God to use any member of the Assembly He willed was not maintained inviolate; nor should you; to do so is going clean in the teeth of God's Word. We are not supposed to swallow, but we are told to judge what every one says, and I do not expect you to lightly swallow what I say, but God's injunction as to the liberty for two or three to speak we must each of us heed, if we are to please Him and keep a good conscience. Whoever speaks must do so as "the oracles of God" (1 Peter 4:11). That is his responsibility, ours is to "prove all things, and hold fast that which is good." We are bound to judge of what is spoken, not critically, but so as to know what is right, and not to sanction what is wrong.

"See that none render to anyone evil for evil, but always pursue that which is good one toward another, and toward all. Rejoice always; pray unceasingly; in everything give thanks, for this [is] God's will in Christ Jesus toward you. Quench not the Spirit; despise not prophecies; but prove all things; hold fast that which is good; abstain from every form of evil" (ver. 15-22).

"Prove all things." By what standard? My own comprehension, or God's revealed word? "Hold fast that which is good."

We here touch a side of our subject, the seriousness of which it is impossible to exaggerate. The apostle, writing to the Corinthians, insisted that there should be no exercise of tongues in the assembly unless the tongues were interpreted (1 Cor. 14:27-28). Why was this? That the assembly might judge what was said. They were responsible to do this even with the greater gift of prophecy (1 Cor. 14:29) They were not to “despise prophesyings,” it is true; but why do not those who refer to this exhortation in fancied support of the admitted vagaries of modern utterances continue the quotation? We are also to “prove all things; hold fast that which is good” (1 Thess. 5:20-21). If one speaks in the assembly the hearers are entitled to prove or test whether it be of God.