Observe here, 1. The character which the apostle gives the false apostles who were crept in amongst the Corinthians: they were corrupters of the word of God; they did sophisticate and adulterate the sincere word of God, by intermixing their own pride and passions, their own inventions and imaginations, with the doctrine which they delivered. False teachers deal with the word, as some vintners deal with their wines; they imbase them in their nature, that they may advance them in their price, and thereby increase their own profit; they deliver the word of God in subtilty, but not in sincerity.
Observe, 2. The declaration which the apostle makes of his own uprightness and integrity in preaching the gospel of Jesus Christ: As of sincerity, as of God, and in the sight of God speak we in Christ; that is, we act as men of sincerity in what we do, as men taught of God and sent by God, as men acted by the power and guided by the Spirit of Christ, and all this is in the sight of God; we speak as from God, of God, in obedience to his command, and with an eye at his glory. He is a better preacher that speaks with an upright heart, than he that speaks with an eloquent tongue; he that acts from religious principles, for holy ends, as in the presence of the all-seeing God, and with a fixed eye at the glory of God in what he preaches, he is an interpreter one of a thousand.