It is impossible to read much from Roman Catholic sources on the church without facing Matt. 16:18-19. "Whatsoever thou shalt bind on earth shall be bound in heaven; and whatsoever thou shalt loose on earth shall be loosed in heaven." This is interpreted as saying heaven will accept and approve the bindings and loosings that originate with men — done first on earth. The same time element is attached to Jn. 20:23, "whosesoever sins ye forgive, they are forgiven unto them..." i.e., men's decisions will be given divine finality.

This concept is crucial to the sacerdotal (priesthood) system, for it makes certain men vicars (representatives and substitutes) for Christ. We see the same principle (though certainly not carried so far) when elders think their decisions are sanctioned by God, and to disobey them is to disobey God. The far reaching effects of such an error is frightening.

been bound in heaven..." The Williams translation reads, “...must be what is already forbidden in heaven." Marshall's Literal English translation reads, "...shall be having been bound" (recognizing the literal import of future perfect). All these are saying the apostles would only bind and loose that which already had the sanction of heaven.

You say, "We (you and I) are not Greek scholars." True! But the principle of this matter is proven by general scriptural context. There is only one lawgiver (Jas. 4:12), and God has not abdicated this right. Even in the limited commission the "Spirit of your father" spake in the disciples (Matt. 10:19-20). As apostles they were to "tarry...until ye be clothed with power from on high" (Lu. 24:48-49) and Jesus told them, "When he, the Spirit of truth, is come, he shall guide you into all the truth...and he shall declare unto you the things that are to come" (Jn. 16:12-13). The apostles bound and loosed by inspiration —which is to say, as earthen vessels (2 Cor. 4:7) they set forth that which was given them from heaven.

So, in complete harmony with truth as a whole, Jesus said that when the apostles bound something in this new dispensation, it would be that which had already been bound it heaven. It would, by the time they bound it, be the message of God via His Spirit. "Shall be bound" (being periphrastic future perfect) carries this meaning. They would not make laws; could not (with inherent right) forgive or retain sins, but would declare what God had already determined about such.