Grace be with you, mercy, and peace, from God the Father, and from the Lord Jesus Christ, the Son of the Father, in truth and love.
Grace be with you. So B, Vulgate; but 'Aleph (') has 'us' for you. Literally, 'Grace shall be with us;' i:e., with both you and me. A prayer, besides a confident affirmation.
Grace ... mercy ... peace. "Grace" covers men's sins; "mercy," their miseries. Grace must first do away with guilt before misery can be relieved by mercy. Therefore grace stands before mercy. Peace is the result of both; therefore stands third. Casting all our care on the Lord, with thanksgiving, maintains this peace (Philippians 4:6-7).
The Lord. So 'Aleph ('); but A B, Vulgate, omit. John never elsewhere uses this title in his letters, but "the Son of God."
In truth and love - the element in which alone grace, mercy, and peace have place. He mentions truth in 2 John 1:4; love, in 2 John 1:5. Paul uses FAITH and love (1 Timothy 1:14); for faith and truth are close akin.