Our pastor will be preaching on the truth of the believer’s confession of the forgiveness of sins as found in the Apostles’ Creed (Art.10) and explained by the Heidelberg Catechism in Q&A 56. In his commentary on the HC, Herman Hoeksema has this to say about the connection between our confession of forgiveness and our confession of the holy catholic church, the communion of saints (Art.9 in the AC):
In the fellowship of the Church, and, therefore, in the communion of saints, the believer lays hold upon this blessing, and makes this confession. This is the connection between the article concerning the Church and that concerning the forgiveness of sins.
Outside of the holy catholic church, the communion of saints, there are no spiritual benefits, the forgiveness of sins cannot be appropriated. If, for some reason, the believer severs himself as far as his conscious life is concerned, from that communion, the first effect of this error is always that he lacks the joy of forgiveness. Perhaps, for a time, he lives in hatred over against some of the brethren; or he envinces an unforgiving spirit; or he seeks the friendship of the world; or he lives in whatever other sin may sever his fellowship with the saints, and disturb the exercise of the communion of saints: in that state of separation from the body of believers, he forfeits the forgiveness of sins (p.88).
And then, after demonstrating this from several passages of Scripture, Hoeksema explains this relation further at the end of this treatment:
Nor is it difficult to understand why this relation between our living in the communion of saints and in the joy of forgiveness exists, and is so inseparable that the one cannot be enjoyed without the other.
It is never in our own power to lay hold on the forgiveness of sins. That we are sorry for sin, repent, seek forgiveness, and obtain it, is the work of Christ Himself. By His Spirit and grace He works the true sorrow after God in our hearts. By that Spirit, He brings us to repentance, leads us to the cross, and assures us of redemption, even the forgiveness of sins in His blood. But that Spirit, on Whose constant indwelling and operation our appropriation of the forgiveness of sins continuously depends, is the Spirit of Christ, and, therefore, the Spirit of the body, that is, the Church. For there is one Lord, and one Spirit, and that one Spirit dwells in the one body. He does not dwell in you or in me, individually, apart from the body, but in the body as a whole, and, in the individual believers, only in fellowship with the body. Hence, outside of that body the Spirit does not operate to bestow the blessings of salvation upon men. If, therefore, through some sin, the believer separates himself from the body, and does not live in the communion of saints, he immediately forfeits the forgiveness of sins.
And as he loses the forgiveness of sins, he necessarily forfeits all the blessings and joy of salvation; for the remission of sins… is basic for all other benefits in Christ.
The article concerning the forgiveness of sins, therefore, occupies a most proper place in the Apostolicum.
By its very position, we are exhorted to keep the unity of the Spirit in the bond of peace! (pp.89-90).
Taken from volume V, Abundant Mercy of Hoeksema’s The Triple Knowledge (Wm.B. Eerdmans, 1949) and now reprinted by the RFPA in the same ten volume format (2015).