Matthew 16:19’s statement about binding and loosening referred to the prerogative of Peter and the other disciples to proclaim Christ’s doctrine with authority, giving a strong basis for the mandate to put obstinate sinners outside the gathering of the apostles (see Matthew 18:17). Their authority lies in the promise that their word is decisive for entrance into the kingdom. Taking that promise seriously means that their admonitions must convey Christ’s promises and demands with the required seriousness.
In Matthew 16:19, it became apparent that the statement about binding and loosening had reference to the prerogative of the apostle Peter along with the other disciples to proclaim Christ’s doctrine with authority. God binds the world to the word of the apostles, and this provides a strong foundation for their mandate to place an obstinate sinner outside the gathering of the apostles (see Matthew 18:17). The disciples possess this authority because they have the promise that their word is decisive for entrance into the kingdom of heaven. Taking that promise seriously means that their admonitions cannot be treated lightly. Were they to do so, they would fail in their duty to convey Christ’s promises and demands with the definitive seriousness it requires.1
18 Truly, I say to you, whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosedin heaven.