Vos:
(d) With respect to children no less than for adults, it is clear from the above that besides the two elements of the offer of the covenant and the obligation of the covenant, there is still a third element present. This consists of the expectation that covenant children will enter into the fellowship of the covenant. This expectation is based on the promise of God to believers that He desires to be their God and the God of their seed and that He also desires to continue His covenant in their seed and to make it a living reality. This does not merely hold true for some promises under certain restrictions, but also for the promises of the covenant, as they span all of life and include every gift of grace. It is, we think, striking how strongly just in this respect the comprehensive character of the covenant is applied by Reformed churches. All of them assume it to be a totality and do not hesitate to unfold it in all its fullness in their liturgical writings. As a promissory covenant its total content is brought into contact with the individual already as an infant. When that infant later enters into covenantal consciousness by active faith, this faith sums up al1 that is included in the covenant, so that the wide, rich world of God’s works of grace is opened up to his sight, a perspective looking backwards and forward. It is just this beautiful outlook which leads one to call the idea of the covenant of grace a "mother-idea." The covenant is a mother because it spiritually bears sons and daughters by the power of divine grace and the promises, a mother because its children have received everything from it, because it has given birth to them, sustains them, feeds, and blesses them. Reformed theology has certainly realized that the church has two sides, and that besides being the assembly of believers and the revelation of the body of Christ, she must also be the means by which new believers are added. But it has not separated these two sides; rather it has kept them in organic connection. Just because the promises of God have been given to the assembly of believers, in its entirety, including their seed, this assembly is also a mother who conceives sons and daughters and is made to rejoice in her children by the Lord. The name "mother" signifies this truly Reformed point of view in distinction from other terms such as "institution of salvation."
As far as we can discover, the leading spokesmen of Reformed theology are completely agreed on this. They all recognize that the church has received such promises for her offspring. They equally recognize that the consideration of these promises is the heart of the fruit of comfort which her view of the covenant offers. And they insist that remembrance of the promise must function as an urgent reason for rousing the seed of the church to embrace the covenant in faith. On both sides, parents and children, this conviction provides strength. Strength was provided in the days of old, in the golden age of the churches, a glorious comfort, finding its most beautiful fruition in the doctrine of the salvation of the children of covenant who die in infancy. Only in the working out of these principles did the theologians diverge to a greater or lesser degree. One could not but expect that a conscious appropriation, an entering into the relation of the covenant by faith and conversion, would be revealed in each member of the covenant who comes to the age of responsibility. The whole tendency of the doctrine of the covenant, as we have tried to present it, led to that demand. One could hardly be satisfied with the thought that a nonrejection of the covenant, where all expression of life was missing, would be sufficient. Here they collided with the discovery, as they also knew from the Scriptures, that not all belong to the seed of the promise. In comparing the statements of theologians at this point, it is clear that the older theologians generally proceeded more fearlessly than the later ones in the individualization and general application of the promises. Beza writes:
The situation of children who are born of believing parents is a special one. They do not have in themselves that quality of faith which is in the adult believer. Yet it cannot be the case that those who have been sanctified by birth and have been separated from the children of unbelievers, do not have the seed and germ of faith. The promise, accepted by the parents in faith, also includes their children to a thousand generations. . . . If it is objected that not all of them who are born of believing parents are elect, seeing that God did not choose all the children of Abraham and Isaac, we do not lack an answer. Though we do not deny that this is the case, still we say that this hidden judgment must be left to God and that normally, by virtue of the promise, all who have been born of believing parents, or if one of the parents believes, are sanctified (Confessio Christianae Fidei, IV, 48).