1 Corinthians 1:6 - Matthew Poole's English Annotations on the Holy Bible

By which knowledge and utterance the testimony of Christ, that is, the gospel, which containeth both the testimony which Christ had given of himself, and which the apostles had given concerning Christ; (the gospel is called the testimony of God, Romans 2:1; 2 Timothy 1:8;) others understand the gifts of, the Spirit (for the Spirit is one of the witnesses upon earth, 1 John 5:8); was confirmed in you; by the miraculous operations wrought by the apostles, as some think; but the way of confirmation here spoken of by the apostle seemeth rather to be understood of their knowledge and utterance. The gospel, and the doctrine of it, and the mission of the Holy Spirit, were confirmed to them and to the world by the knowledge which God had given the apostles, and these Corinthians, of the great things of God; and their ability to communicate this knowledge unto others, for the honour of God, and the good of others.