What does the Bible say about being zealous / having zeal?

It may sound strange to some of you but the fact is there are a lot of people in this city who are religious, very religious, and yet not saved. In spite of their religion they are unforgiven sinners, they do not know God and are on the broad road that leads to destruction. If you challenge my statement I answer, This tenth chapter of Romans is my authority for it. Paul, the great apostle, was not the sort of man to waste his time praying for something that had already happened, and here he tells us that he was praying for Israel, that they might be saved. Then they were not saved, yet they were religious, they were zealous, they were doing their best. "They have a zeal for God," said the apostle, "but not according to knowledge," and it should be plain to everybody that the greater a man's zeal the worse it is for him if he is wrong. The more zealous a man is on the wrong road the further he is carried from the right destination. A false religion is the greatest curse a man can suffer from, for he is blinded to the truth, he is deceived, he thinks he is right when he is wrong, his ignorant zeal is his undoing.

It may sound strange to some of you but the fact is there are a lot of people in this city who are religious, very religious, and yet not saved. In spite of their religion they are unforgiven sinners, they do not know God and are on the broad road that leads to destruction. If you challenge my statement I answer, This tenth chapter of Romans is my authority for it. Paul, the great apostle, was not the sort of man to waste his time praying for something that had already happened, and here he tells us that he was praying for Israel , that they might be saved. Then they were not saved, yet they were religious, they were zealous, they were doing their best. “They have a zeal for God,” said the apostle, “but not according to knowledge,” and it should be plain to everybody that the greater a man's zeal the worse it is for him if he is wrong. The more zealous a man is on the wrong road the further he is carried from the right destination. A false religion is the greatest curse a man can suffer from, for he is blinded to the truth, he is deceived, he thinks he is right when he is wrong, his ignorant zeal is his undoing.

"For I bear them witness that they have zeal for God, but not according to knowledge." "Zeal of God" is an objectionable rendering, like "faith of the Son of God" in Galatians 2:20. The Greek genitive is far more comprehensive than the English possessive case, and admits of an objective force as readily as a subjective. "The love of God" in that tongue equally means God's love to us or ours to Him: the context alone decides. Here there can be no question of the intended force. The Jews were zealous for God but not according to right or true knowledge (κατ᾽ ἐπίγνωσιν). This filled the apostle's heart with so much the more affectionate care; for their zeal carried them the farther in the wrong direction, as ever must be in divine things where faith does not regulate according to the revealed mind of God.

Israel's Mistake. — Israel sought for righteousness is the testimony of the apostle, whose heart's desire and prayer to God was for them that they might be saved. Wholly wrong were they in the way that they sought for it, as the prayer for their salvation indicated. Who wants salvation from the wrath to come, who can commend himself to God by his own righteousness? The apostle's view, then, of their condition, and the way to have it met, was wholly at variance with the light in which they regarded the matter. Both were in earnest — the apostle for them, and they for themselves. He prayed for them. They went about to establish their own righteousness. Zeal for God they certainly had, but not according to knowledge. Earnestness of purpose, too, characterised them. Busily engaged they were in attempting to establish their own righteousness. Here, then, an important question for them and for us was openly raised, and, as we see, definitely settled. Will zeal for God in itself commend any sinful creature to Him? Will earnestness of purpose be sufficient to draw down on the individual the approbation of Heaven? Earnestness without subjection to God's Word will not help those to whom that Word has come. Zeal without knowledge! That characterised the Jew. How was it shown? Let the apostle speak. For who was more qualified to treat of this than one whose former state those words fitly described? "They being ignorant of God's righteousness, and going about to establish their own (righteousness here is generally omitted), have not submitted themselves to the righteousness of God?" (10:3). Self was at the bottom, combined with ignorance of man's ruin by the fall. Hence they did not submit themselves to the righteousness of God. They would not let God show His righteousness in justifying such ungodly creatures. They were not willing to be illustrations in display of that righteousness.

Rom. 10:2-3. Nor does he fail to bear them witness that they have zeal for God, but not according to knowledge. "For they being ignorant of God's righteousness, and going about seeking to establish their own righteousness have not submitted themselves unto the righteousness of God." Their zeal, which had for its object the righteousness of man according to the law, was the obstacle which hindered their knowing the righteousness of God and submitting to it. When God presented His righteousness, offering it to Israel in their own Messiah, they rejected Him. They failed in their own righteousness and what was worse, they would not submit to God's.

Observe that Paul says here of Israel, "For I bear them record that they have a zeal of God, but not according to knowledge." I think there are still a great many men of this class. They have a zeal of God. They have thoughtful minds, and all young fellows are not careless. I believe students are considered a careless lot. That is quite true in the main, but a great many are thoughtful. A large proportion of those who come to hear my voice are thoughtful men. The apostle says, "I bear them record that they have a zeal of God, but not according to knowledge." Now, such a man is doing his best to get saved. He has zeal, but not according to knowledge. Are you hard at work trying to mend your ways, and to do what you think is necessary for your salvation? I commend you for your zeal, but it is not according to knowledge, because the man who has had his eyes opened to the truth has learned this, I can do nothing.

Yet Israel's zeal for God was unquestionable, as Paul bears record. Did he not know it well in his unconverted days? Persecuting Christians, he thought he was doing God service. How many ways seem right to men, though the end is the way of death! Zeal in such a case is only to be the more pitied. Zeal for God is of greatest danger, when not stemming from the knowledge of God.

He prays, and prays with a right desire, for the salvation of Israel. He prays in the Spirit for that which he well knew to be the final purpose of God towards His people. But his prayer is the more earnest in their behalf because of his ability to bear witness to their zeal to God-ward. And surely none could speak with a fuller appreciation of what be said on this subject than the writer of this Epistle (Acts 22:3). He could thoroughly sympathize with a zeal which had once been the distinctive honour of his own name as a child of tradition, while exposing, as an apostle of truth, the futility and total unprofitableness of such zeal. Thus, while he could find it in his heart to make their zeal for God a ground of advocacy for that nation as distinguished from the nations who cared not for God, he has to pronounce as from God the entire rejection of that which, unless produced and directed by the Spirit of truth, is but a dead work of the flesh. Zeal not according to knowledge ever turns in its result to envy and hatred of that which is of God. "He has spoken blasphemy" was the decision which led to the cry, "Away with Him, away with Him, crucify Him." "Why persecutest thou me?" was the question which awakened the most zealous of those who thought to do God service by shedding the blood of His saints, to the fearful discovery that that which his self-satisfied heart most gloried in was the direst of all sins against God.

AS WE OPEN this chapter, we find Paul standing before this august body, and we might have expected him to give the most striking and convincing address of his life. In result however there was a minimum of testimony and a maximum of confusion. Paul's opening remark was bitterly resented, though we can see that it was true. A "good" conscience is acquired and maintained as we sincerely and rigidly carry out all that conscience directs. The zealot with unenlightened or perverted conscience does the most outrageous things in order to preserve his "good" conscience. Thus had Paul acted in his unconverted days, and since his conversion he had with sincerity observed the warnings of his conscience, now enlightened and rectified. How clearly this shows us that conscience is of itself no safe guide: it must be enlightened by the Word of God. Its value depends entirely upon the measure in which it is controlled by the Word.

We may be very zealous for the glory of God; but the greater our zeal is, the more harm it will do if it is not according to knowledge; we shall spoil everything, like David in chapter 13, if we do not understand our incapacity and dependence; and we can only acquire the knowledge that we need, in order that our zeal be not destructive, by consulting the Lord.