Argum. 1st.  The keys of the kingdom of heaven were never given by Christ to the civil magistrate, as such:  therefore he cannot be the proper subject of church government as a magistrate.  We may thus reason: 

Major.  No power of the keys of the kingdom of heaven was ever given by Christ to the civil magistrate, as a magistrate.

Minor.  But all formal power of church government is at least part of the power of the keys of the kingdom of heaven.

Conclusion.  Therefore no formal power of church government was ever given by Christ to the civil magistrate, as a magistrate.

The major proposition is evident.

1.  Because when Christ gave the keys of the kingdom of heaven, he makes no mention at all of the civil magistrate directly or indirectly, expressly or implicitly, as the recipient subject thereof.  Compare Matt. xvi. 19, and xviii. 18, John ii. 21-23, with Matt. xxvii. 18-20. 2.  Because, in Christ’s giving the keys of the kingdom of heaven, he makes express mention of church officers,[32] which are really and essentially different from the civil magistrate, viz. of Peter, in name of all the rest, Matt. xvi. 18, 19, and of the rest of the apostles as the receptacle of the keys with him, Matt. xviii. 18, all the disciples save Thomas being together, he gave them the same commission in other words, John xx. 20-24, and Matt. xxviii. 18-20.  Now if Christ should have given the keys, or any power thereof to the magistrate, as a magistrate, he must consequently have given them only to the magistrate, and then how could he have given them to his apostles, being officers in the Church really distinct from the magistrate?

3.  Because Jesus Christ, in giving the keys of the kingdom, gave not any one sort, act, part, or piece of the keys severally, but the whole power of the keys, all the sorts and acts thereof jointly.  Therefore it is said, I give the keys of the kingdom—­and whatsoever thou shalt bind—­whatsoever thou shalt loose—­whose soever sins ye remit—­whose soever sins ye retain—­Matt. xvi. 19, John xx. 23.  So that here is not only key, but keys given at once, viz. key of doctrine, and the key of discipline; or the key of order, and the key of jurisdiction; not only binding or retaining, but loosing or remitting of sins, viz. all acts together conferred in the keys.  Now if Christ gave the keys to the magistrate, then he gave all the sorts of keys and all the acts thereof to him:  if so, the magistrate may as well preach the word, and dispense the sacraments, &c., (as Erastus would have him,) as dispense the censures, &c., (for Christ joined all together in the same commission, and by what warrant are they disjoined?) and if so, what need of pastors, teachers, &c.,, in the Church?  Let the civil magistrate do all.  It is true, the ruling elder (which was after added) is limited only to one of the keys, viz. the key of discipline, 1 Tim. v. 17; but this limitation is by the same authority that ordained his office.