I’m doing a series of sermons on the covenant of grace and so I’ve been doing some reading again on this subject. A lot has been written about the doctrine of the covenant in Reformed circles. J. Kamphuis wrote a little book called An Everlasting Covenant. It was originally written in Dutch and then translated and published in Australia in 1985.
In our Form for Infant Baptism, the first question asks whether parents confess that our children “though conceived and born in sin, and therefore subject to all sorts of misery, even to condemnation, are sanctified in Christ and thus as members of his church ought to be baptized?” The words in bold have been controversial and Kamphuis discusses this in his book. Let me quote what he writes about the views of Klaas Schilder:
K. Schilder…expounded the view of the old Reformed theologians such as Petrus Dathenus and Marten Micronius, and also that of the baptismal form as follows:
a. ‘Sanctified in Christ’ means: by virtue of the participating in the Covenant, being entitled to the promises of justification by Christ’s blood;
b. This justification, however, in time becomes our share through faith.
c. When by faith the promise of the washing by Christ’s blood is accepted, and in this way the baptized person indeed participates in justification, then the washing by Christ’s Spirit springs from it, sanctification not ‘IN Christ‘ but ‘THROUGH the Spirit.’
d. This is why at baptism — which has the participation in the promise as the foundation of its administration, and itself seals that promise — the baptized person is put under the obligation to believe the promise.
e. It belongs to the contents of the promise that has to be embraced in faith, that the Holy Spirit desires to sanctify us, (indeed) imparting to us that which we have in Christ (in the promise, by rights). (80)
In other words, baptism does not actually convey the gift of justification, as if all those who are baptized are automatically justified and then might later lose it. It conveys the promise, but what is promised is only received through faith. All covenant children are recipients of the promises and all are obligated to believe those promises. The gospel call to faith and repentance needs to be sounded amongst the covenant people!