Basil of Caesarea — on 2Cor 3:6 (CONCERNING BAPTISM 1.2)

“The difference between the spirit and the letter the apostle explains succinctly in another place by comparing the law and the gospel, saying: "For the letter kills, but the spirit gives life." By the "letter" he means the law, as is evident also from what precedes and follows. By the "spirit" he means the Lord's doctrine, for the Lord himself said: "My words are spirit and life."33.”