Yes amy, the KJV says "OF" but some of the other versions has changed the wording to read "IN" which takes it away from Christ and gives it to man, which is wrong.
I have the Hebrew/Greek Interlinears by Jay Green-which I highly reccomend, btw-and in Gal. 2:16, it has "faith IN Christ". Granted the words "of" and "in" are in
italics, so as to make the translation from Greek to English could be smoother. Faith "in" Christ seems to be the proper text, imo. The "faith of Christ" has an odd feel to it. Christ needs to have faith in/of nothing.
Galatians 2:16
King James Version (KJV)
16Knowing that a man is not justified by the works of the law, but by the faith of Jesus Christ, even we have believed in Jesus Christ, that we might be justified by the faith of Christ, and not by the works of the law: for by the works of the law shall no flesh be justified.
Galatians 2:16
Young's Literal Translation (YLT)
16having known also that a man is not declared righteous by works of law, if not through the faith of Jesus Christ, also we in Christ Jesus did believe, that we might be declared righteous by the faith of Christ, and not by works of law, wherefore declared righteous by works of law shall be no flesh.'
Galatians 2:16
Wycliffe Bible (WYC)
16 know that a man [soothly knowing for a man] is not justified of the works of the law, but by the faith of Jesus Christ; and we believe in Jesus Christ, that we be justified of the faith of Christ [that we be justified by the faith of Christ], and not of the works of the law. Wherefore of the works of the law each flesh shall not be justified.
Galatians 2:16
New Living Translation (NLT)
16 Yet we know that a person is made right with God by faith in Jesus Christ, not by obeying the law. And we have believed in Christ Jesus, so that we might be made right with God because of our faith in Christ, not because we have obeyed the law. For no one will ever be made right with God by obeying the law.”[a]
Galatians 2:16
New International Version 1984 (NIV1984)
16 know that a man is not justified by observing the law, but by faith in Jesus Christ. So we, too, have put our faith in Christ Jesus that we may be justified by faith in Christ and not by observing the law, because by observing the law no one will be justified.
Galatians 2:16
Lexham English Bible (LEB)
16 but knowing that a person is not justified by the works of the law, if not by faith in Jesus Christ,[a] and we have believed in Christ Jesus so that we may be justified by faith in Christ
and not by the works of the law, because by the works of the law no human being will be justified[c].
16 know that no one is justified by the works of the law but by faith in Jesus Christ.[a] And we have believed in Christ Jesus so that we might be justified by faith in Christ and not by the works of the law, because by the works of the law no human being will[c] be justified.
Galatians 2:16
American Standard Version (ASV)
16 yet knowing that a man is not justified by the works of the law but through faith in Jesus Christ, even we believed on Christ Jesus, that we might be justified by faith in Christ, and not by the works of the law: because by the works of the law shall no flesh be justified.
Galatians 2:16
Contemporary English Version (CEV)
16But we know that God accepts only those who have faith in Jesus Christ. No one can please God by simply obeying the Law. So we put our faith in Christ Jesus, and God accepted us because of our faith.
Now, two of the versions I posted here, have footnotes stating it could be "of" instead of "in". So who really knows? I look at consistency, and "in" seems moreso than "of".