In commenting on Ephesians 4:12, Calvin says:
That those who neglect this instrument [“the external ministry of the word” i.e. regular attendance at the public preaching of the word] should hope to become perfect in Christ is utter madness. Yet such are the fanatics, on the one hand, who pretend to be favored with secret revelations of the Spirit, — and proud men, on the other, who imagine that to them the private reading of the Scriptures is enough, and that they have no need of the ordinary ministry of the church. If the edification of the church proceeds from Christ alone, he has surely a right to prescribe in what manner it shall be edified. But Paul expressly states, that, according to the command of Christ, no real union or perfection is attained, but by the outward preaching. We must allow ourselves to be ruled and taught by men. This is the universal rule, which extends equally to the highest and to the lowest. The church is the common mother of all the godly, which bears, nourishes, and brings up children to God, kings and peasants alike; and this is done by the ministry. Those who neglect or despise this order choose to be wiser than Christ. Woe to the pride of such men!