If we will acknowledge the ministry a particular office in the church of Christ … then we must also confess it is not anyone’s work, though never so able, except called to the office….
Those that are not sent and commissionated by God’s call for ministerial work, they may speak truths as well as they that are, yet of him that acts by virtue of his calling, we may say that he preacheth with authority, and not like those that can show no commission, but what the opinion themselves have of their own abilities give them.
– William Gurnall, The Christian in Complete Armour, p. 285