Church and Covenant, Visible and Invisible

The visible church is composed of all those who profess the true religion and their children (1 Cor. 1:2, 7:14). The invisible church is composed of all the elect (John 10:16, 29). These are both legitimate ways to speak of the one church of Jesus Christ. 

Not all who are in the visible church are members of the invisible church. Some of them are not elect and never come to saving faith in Christ, although they may profess to believe. (There are also some who are members of the church in both senses and yet are unsaved at the moment, their conversion being still future.) The church is being gathered through the visible administration of the covenant and presently contains a mixture, but it shall be purified and made perfect in the end (Matt. 13:47-50, 22:8-14). 

We can apply the same distinction when speaking of covenant membership. Those who profess the true religion and their children are members of the covenant of grace in its visible administration, but in another sense, the covenant of grace is made with Christ as the last Adam and in him all the elect.

The children of believers are visible saints, members of the visible church like their parents. This is why they are baptized as infants. As the Westminster Directory for Public Worship (1645) put it, the children of believers “are Christians, and federally holy before baptism, and therefore are they baptized…” They are to be raised as disciples of Christ. And all members, young and old, ought to be regularly encouraged to believe in Christ, to make use of the means of grace, to repent of their sins, and to grow in Christ.