18 But as surely as God is faithful, our message to you is not “Yes” and “No.”

Read 2 Corinthians 1:18 Using Other Translations

But as God is true, our word toward you was not yea and nay.
As surely as God is faithful, our word to you has not been Yes and No.
As surely as God is faithful, our word to you does not waver between “Yes” and “No.”