For those who want to know more about the Papacy, the interpretation of Matthew 16:18 and its understanding by the Early Church fathers, I recommend Dr. James White’s debate vs Father Mitch Pacwa. It is a very insightful and respectful debate.
The Whole Number Of The Elect
The Confession claims that the universal and invisible church “consists of the whole number of the elect, that have been, are, or shall be gathered into one, under Christ” which undoubtedly includes believers prior to the establishment of the New Covenant in Christ’s blood. But how is this the case? As we have argued and tried to show in chapter 7 on Covenant Theology, the Covenant of Grace, in 1689 Federalist understanding, is the New Covenant in promise form. It was not a formal covenant as the others were. The fact that all the saints, both prior to the physical coming of Christ and after the coming, are included in the universal church is seen in Hebrews 12:22-24. Here, the church on earth joins with the church in heaven. In worship, we come to the assembly or the church “of the firstborn who are enrolled in heaven”. John Gill comments on this passage:
the church of God, consisting of all his elect, both Jews and Gentiles, and the meeting of them together: they met together, in the infinite mind of God, from all eternity; and in Christ, their head and representative, both then and in time; and at the last day, when they are all gathered in, they will meet together personally; and a joyful meeting it will be; and a very general one, more so than the assembly of the Jews, at any of their solemn feasts, to which the apostle may have some respect; since this will consist of some of all nations, that have lived in all places, and in all ages of time[8]
If it was the blood of Christ which saved all saints, in all ages and under all the covenants, then they belong to Christ and His assembly. He is their Mediator and He is the Mediator of only one covenant, the New Covenant in His blood. If He stood for them before God, He stood as the Mediator of the New Covenant or the Covenant of Grace on their behalf. Therefore, they had to be members of the New Covenant or people who have been chosen to be in the New Covenant for Christ to represent them. This was, in fact, the covenant that the believers under the Old Testament were called into (Heb. 9:15-17; see here also). Dr. Sam Waldron observes that
the church is the climactic earthly expression of the people of God. Thus language is frequently used which equates the church with all those in union with Christ. The church is the body and bride of Christ (Eph. 1:22; 4:11-16; 5:23-27, 29, 32; Col. 1:18, 24). Furthermore, the bride of Christ is composed in the last day of the saved from every age (Eph. 5:27; Rev. 21:9-14; note also Matt. 8:11-12; John 10:14-17; Heb. 11:39-40). Thus the church will one day be composed of all the redeemed. As the people of God, the church does consist ‘of the wh...