2 Corinthians 1:18

(18) As God is true.—Literally, as God is faithful. The words were one of St. Paul’s usual formulæ of assertion. (Comp. 1 Corinthians 1:9; 1 Corinthians 10:13; 2 Thessalonians 3:3.) In other instances it is followed commonly by a statement as to some act or attribute of God. Here it is more of the nature of an oath: “As God is faithful in all His words, so my speech” (the vague term is used to include preaching, writing, personal intercourse) “is true and faithful also.” There had been no “Yes” and “No” in the same breath; no saying one thing when he meant another.