From this it will also be evident that conversion has two aspects. These two aspects the Catechism describes in Questions and Answers 89 and 90. The one aspect is what the Scriptures and the Catechism both call the mortification of the old man, which by the Catechism is described in a profoundly spiritual way as “a sincere sorrow of heart, that we have provoked God by our sins; and more and more to hate and flee from them.” And the second aspect is called the quickening of the new man, which again is described in the same deeply spiritual way by saying that “it is a sincere joy of heart in God, through Christ, and with and delight to live according to the will of God in all good works.”
The first aspect, therefore, is the mortification, or the putting off, of the old man, the mortification of our members which are upon the earth. The first and principal characteristic of this mortification of the old man is, according to the Heidelberg Catechism, a sincere sorrow of heart that we have provoked God by our sins, in other words, true repentance. By the experience of this sincere sorrow of heart you may certainly know that you are converted, no matter whether this conversion was gradual or sudden. If you wonder sometimes whether or not you are converted, it is well to ask yourself the question whether you are truly sorry for sin. Surely, the chief characteristic of true conversion in this life, in which we have but a small beginning of the new obedience, is not that you are always on the mountain tops of faith, and perform many wonderful good works, but that you repent in true sorrow after God. Perhaps you ask: how do I know that my sorrow over sin is genuine? Also that question is really not difficult to answer. There is, indeed, a sorrow that is not after God, a false, a counterfeit sorrow. It is what Scripture calls the sorrow of the world. The two, however, the sorrow after God and the sorrow of the world, may easily be distinguished. True sorrow after God is rooted in the love of God, while the sorrow of the world is really, principally love of self. The former is a sorrow, as the Catechism expresses it, that we have provoked God by our sins. It is sorrow over sin as sin, because sin is contrary to the will of God. The sorrow of the world, on the other hand, is sorrow not over sin, but rather over the evil consequences of sin for ourselves. Counterfeit sorrow over sin really rejoices in iniquity. And it would freely indulge in it, if it were not for the fact that the wages of sin are always death. It is this that the sorrow of the world regrets. True sorrow over sin is a radical break with all sin. But counterfeit sorrow is a break with certain sins, and that only to the degree that their commitment appears dangerous and harmful for the time being. Therefore, godly sorrow leads to life and salvation. Or as the apostle expresses it in II Cor. 7:10, it “worketh repentance to salvation not to be repented of.” But the sorrow of the world worketh death. The latter really plays with sin. It loves the darkness rather than the light. It likes to go the way of sin as far as possible, without experiencing the evil consequences of a life of corruption. And the result is always death. But true sorrow over sin is a sure manifestation of conversion.
But of course, this sincere sorrow after God, that we have provoked Him by our sins, manifests itself in the fact that we more and more hate sin and flee from it. This is the seal upon our true repentance. We may be sure: if this seal is not present, we were never sincerely sorry over sin. To mortify the deeds of the body, to crucify our old nature, and to walk in in a new and holy life in principle is the sure and inevitable sign of true conversion. If we do not really hate sin, we cannot be filled with sorrow after God. And if we do not fight sin and flee from it, but rather seek it, we thereby reveal that we do not hate it.
Again, we must remember that this mortification of the old man is first of all the work of God, and that our act of mortifying the flesh and the deeds of the body is the fruit of God’s work. This is evident from all Scripture, but it is emphatically and beautifully taught in Romans 6. There the apostle asks the question: “Shall we continue in sin, that grace may abound”? And he answers that question by teaching that this is impossible, because we were baptized into Jesus Christ, and therefore were baptized into His death. We have been buried with Christ by baptism into His death. And we have been planted together in the likeness of His death. Therefore, the apostle concludes in vs. 6: “Knowing this, that our old man is crucified with him, that the body of sin might be destroyed, that henceforth we should not serve sin.” It is on the basis of this principal crucifixion of the flesh that the apostle continues: “Let not sin therefore reign in your mortal body, that ye should obey it in the lusts thereof. Neither yield’ ye your members as instruments of unrighteousness unto sin.” vss. 12, 13. But even thus all is not said. It is not so, that God converts us principally, so that we are dead with Christ and crucified with Him, and that now we finish our own conversion. On the contrary, only when God works in us continually to will and to do of His good pleasure, are we able to be active in the mortification of our old man. Never is there any synergism between God and us in the work of salvation and of conversion. It is all the work of God. And our mortification of the old man is the fruit of the operation of the grace of God in us. This is effected by the Spirit of Christ, who dwells in us, and by the efficacious calling through the preaching of the Word of God.
The other, or positive, aspect of conversion is the turning to God and to the way of His precepts. Or, as the Catechism expresses it, it consists in “a sincere joy of heart in God, through Christ, and with love and delight to live according to the will of God in all good works.” This is the quickening of the new man. Of this the apostle Paul writes in Eph. 4:22-24: “That ye put off concerning the former conversation the old man, which is corrupt according to the deceitful lusts; And be renewed in the spirit of your mind; And that ye put on the new man, which after God is created in righteousness and true holiness.” Also the quickening of this new man is first of all and principally the work of God. And our active participation in the putting on of the new man is never anything else than the fruit of the work of God’s grace in our hearts. This is also taught in the same chapter of the epistle to the Romans from which we quoted above. For we were not only buried with Christ by baptism into His death, but we were also raised with Him unto newness of life: “For if we have been planted together in the likeness of his death, we shall be also in the likeness of his resurrection.” And again, in vs. 11: “Likewise reckon ye also yourselves to be dead indeed unto sin, but alive unto God through Jesus Christ our Lord.” It is upon the basis of this work of God that the apostle admonishes the church not only to mortify the old man, but also to yield themselves unto God as those that are alive from the dead, and their members as instruments of righteousness unto God. vs. 13. This yielding of our members as instruments of righteousness unto God is our act of putting on the new man. It signifies the constant endeavor to place ourselves and our whole life under the gracious dominion of the new life in Christ. As the Catechism has it, the quickening of the new man is “a sincere joy of heart in God, through Christ, and with love and delight to live according to the will of God in all good works.” And also this putting on of the new man is not accomplished without the operation of the Spirit of God in Christ. It is not so, that we are once risen with Christ, and that for the rest we put on the new man by our own effort. The contrary is true: God is always first. And only when He continuously works in our hearts by His Holy Spirit can we be active, as the fruit of His grace in us, in putting on the new man. And also this active part of our conversion is accomplished by the Spirit through the efficacious calling in the preaching of the Word.
You will readily understand that conversion is a matter that concerns our whole life as long as we are in this world. Its beginning may be either very sudden and striking, so that you can point to the place and the hour when this wonder of grace was first performed on your soul; or it may be gradual and unnoticeable, bound up with the early years of your childhood, so that you cannot at all remember that you ever were converted. The former is usually the case with those that live in ways of gross sin until they have reached the age of maturity. God suddenly stops them in their pursuit of sin, and turns them radically about. The latter naturally occurs when we are instructed in the truth of the gospel from infancy, learn to stammer our prayers on mother’s lap, never depart from the fear of the Lord, but walk in His way from childhood. It should also be remarked that the latter is far preferable to the former, and that he who can mention the date and the place of his conversion has nothing to boast because of it. By all means, let him not make of the experience of his sudden conversion a ground of confidence that he really is converted. Often, it seems, this is done. You may frequently hear people boast that they know that they are converted because some ten or twenty years ago they came to Christ. But the question is not at all how and when you were converted, nor whether you had an experience of conversion several years past, but whether you are converted today. For whether you were converted suddenly or gradually, as far as the beginning of your conversion is concerned, it surely is only a beginning. It must continue throughout your whole life. It is never finished until you close your eyes forever upon things mundane, your body is laid in the grave, and your soul is with Christ in glory. Nor must we ever imagine that conversion gradually becomes less necessary as we grow in grace. The contrary is true. Always there is with the Christian the old man, seeking to regain his former dominion. And never does he get rid of the body of this death. Always the new man in Christ must watch and pray and fight the good fight. We must be converted, and convert ourselves, as long as we live. But remember; the latter is always the fruit of the former. Let no flesh glory in His presence.