The Scofield Bible Commentary, by Cyrus Ingerson Scofield, [1917], at sacred-texts.com
We who are
Paul here quotes from his words to Peter when he withstood him at Antioch to show the Galatians that, whatever the legalists may have pretended, Peter and he were in perfect accord doctrinally. Paul appealed to the common belief of Peter and himself as a rebuke of Peter's inconsistent practice.
sinners
Sin
(See Scofield) - (Rom 3:23).
we seek
That is, "we" Jews. (Rom 3:19-23). The passage might be thus paraphrased: If we Jews, in seeking to be justified by faith in Christ, take our places as mere sinners, like the Gentiles, is it therefore Christ who makes us sinners? By no means. It is by putting ourselves again under law after seeking justification through Christ, that we act as if we were still unjustified sinners, seeking to become righteous through law-works. (Gal 5:1-4).
sinners
Sin
(See Scofield) - (Rom 3:23).
transgressor
Sin
(See Scofield) - (Rom 3:23).
not I
See note, (See Scofield) - (Eph 4:24).
grace
Grace (in salvation). (Gal 5:4); (Rom 3:24).
(See Scofield) - (Joh 1:17).
righteousness
(See Scofield) - (Rom 10:10).