What is authority in a preaching ministry?
It is a consequent of unction, and not of office. The scribes had an outward call to teach in the church; but they had no unction, no anointing, that could evidence they had the Holy Ghost in his gifts and graces. Christ had no outward call; but he had an unction,—he had a full unction of the Holy Ghost in his gifts and graces, for the preaching of the gospel. Hereon there was a controversy about his authority. The scribes say unto him, Mark xi. 28, “By what authority doest thou these things? and who gave thee this authority?” The Holy Ghost determines the matter, Matt. vii. 29, “He preached as one having authority, and not as the scribes.” They had the authority of office, but not of unction; Christ only had that. And preaching in the demonstration of the Spirit, which men quarrel so much about, is nothing less than the evidence in preaching of unction, in the communication of gifts and grace unto them, for the discharge of their office: for it is a vain thing for men to assume and personate authority. So much evidence as they have of unction from God in gifts and grace, so much authority they have, and no more, in preaching: and let every one, then, keep within his bounds.
Owen’s point is that you don’t get the authority to preach from the institution that hands you a degree. You don’t get your authority from the ordination of your assembly you are membered in. Authority comes from God. All the rest, is merely a garnish and an outward approval, but not a requirement.