Jamieson, Fausset and Brown on James 2:9

9. Respect of persons violates the command to love all alike "as thyself."

ye commit sin--literally, "ye work sin," Mt 7:23, to which the reference here is probably, as in Jas 1:22. Your works are sin, whatever boast of the law ye make in words (see on Jas 2:8).

convinced--Old English for "convicted."

as transgressors--not merely of this or that particular command, but of the whole absolutely.