…if we turn now to the unfolding of the excellence of Reformed doctrine, let us take note of the principle of the Reformed faith, which is to exalt and to glorify God to the very highest, and to humble man to the deepest depths. We see then immediately a most noteworthy difference from all other teachings outside the Reformed faith, since they all, no matter how in principle they may differ, agree in this one point: they seek the ability to draw near to God from a power in themselves, while the Reformed faith supposes as a principle an immediate work of God in man for him to come to God. Because of this, it is also true that all who cleave to doctrinal teachings outside of the Reformed faith, including those who only in name are affiliated with the Reformed system, discover that they are compatible, and having a similar outlook, they can unite; but they always are opposed to the true confessors of the Reformed worship of God, because Reformed believers start from a principle that diametrically contradict theirs.
And now proceeding from this eternal principle of God, the true member of the Reformed church confesses an eternal, triune, covenant God as the one principle of his salvation. He confesses that the triune God through mutual consultation, in eternity past, without beginning, has determined the salvation of everyone who will be called in time. He confesses that it is the Holy Spirit, through the application of the elective grace of the Father and the Son’s blood of reconciliation, who brings that salvation to his heart. The person called of the Lord senses that he has been translated into a new life through the powerful and irresistible working of that Spirit. Having been transported into the new life in that faith, he by that faith receives the assurance of this salvation and realizes that in fact he has been purchased by the Lord Jesus Christ and belongs to Him.
He confesses that he has received peace with God through God’s work in him, that he may now worship God the Father as his Father, because he is covered by the surety-righteousness of his Redeemer, Jesus Christ. He confesses that, as a consequence of this abounding grace, he senses a strong inclination to glorify God continually through His law and His commandments, so that it is his desire to honor God above everything and to love his neighbor. He now feels that he is God’s workmanship in Christ Jesus unto good works, which were ordained for Him so that he may walk therein. Since he feels that the principle of his blessed hope is not in him or in anything from him, but is wholly derived from a power of God in him, he confesses especially that he has, according to the scriptures, an assurance of his salvation in Christ Jesus, because of which he, like Job, may say, I know that my Redeemer liveth (Job 19:25).
However, since God is his teacher who instructs him in true doctrine, and since he discovers nothing for his salvation in himself that is not of God, he discerns clearly that the doctrine in which he awaits his full salvation by God is the fundamental principle of the knowledge that will be revealed to him in eternity, that he may truly know God the Father in Jesus Christ whom He has sent. This causes him to be assured that the doctrine that is from God and returns to God and that he confesses by God’s grace is the one doctrine of God’s good pleasure.
It is superfluous to present more support for the excellence of Reformed doctrine, far above other teachings that are foreign to it, since it is sufficient to demonstrate its godly principle and to regard all competitors as having no value whatsoever. If we compare the doctrine the spirit of this age has produced with the Reformed doctrine as I have explained it, then it will not be difficult to apply to those who oppose this faith the saying of the Lord Jesus Christ concerning the doctrine of the scribes and Pharisees in His day: You are from below, earthly, while of the Reformed faith it can be said, You are from above out of heaven (John 8:23).
If we examine the development of these two diametricaly opposing principles, what do we see? That by the one, having been puffed up with the idea of his own worth, man is urged along in his sinful existence and all his actions necessarily are marked by this pride, while the behavior of him who is ruled by a godly principle is inclined toward the honor of God’s name and is always directed toward a sanctified purpose. If we proceed further and investigate how these two completely opposing principles exercise a powerful influence upon a whole nation, so that from the one nothing but the turmoil of the evil inclinations of man must be manifested and, no matter how covered up and hidden from view, the proud heart of man becomes the motivator of all its deeds, while the other principle, always leading to God and His commandments, works a quiet and peaceful existence of heart and spontaneously provides to everything the essence of what is just, holy, honorable, and fitting- having made that examination, it should not be too difficult to see how we have fallen away from our fathers and have become estranged from their virtues and values.
1834: Hendrik De Cock’s Return to the True Church, pp. 88-91