Any man may read the Scriptures, or make an oration to the people; but it is not that which the Scriptures call preaching the word of God, unless he be sent by God to do it; for “how can they preach except they be sent?” A butcher might kill an ox or a lamb, as well as the high-priest; but it was no sacrifice to God, unless one of His priests did it.

“And no man taketh this honour unto himself, but he that is called of God, as was Aaron.” Any man may treat of public affairs as well as an ambassador; but he cannot do it to any purpose without a commission from his prince.

If I was not fully assured that I had a commission to be an ambassador for Christ, and to act in His name, I should never preach or execute any ministerial office; for I am sure that all I did would be null and void of itself, according to God’s ordinary way of working; and we have no ground to expect miracles.