For comparison, the NKJV:Galatians 2:16 Knowing 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.
I consulted several modern major translations and they render it like the NKJV. I consulted Young's Literal Translation, and an Interlinear Bible, and it appears that the KJV renders the passage more literally.16 knowing that a man is not justified by the works of the law but by faith in Jesus Christ, even we have believed in Christ Jesus, that we might be justified by faith in Christ and not by the works of the law; for by the works of the law no flesh shall be justified.
As someone who does not understand Greek, perhaps the modern translators convey the meaning correctly. But the more literal rendering seems to change the meaning. The faith spoken of is not that of the believer, even though their faith is mentioned "...we have believed". But by our belief in Christ, we might be justified by HIS faith. Perhaps his faith in the Father, in his purpose in emptying himself and becoming incarnate and being crucified, to do the will of the Father who sent him. Or perhaps the faith we have received, or been made able to receive, by an act of grace on his part.
Likewise, in verse 20
Jesus, who had faith in the plan of the Father, and faith in those who would in turn have faith in him, and loved them, gave himself for them.20 I am crucified with Christ: nevertheless I live; yet not I, but Christ liveth in me: and the life which I now live in the flesh I live by the faith of the Son of God, who loved me, and gave himself for me.
These are just some thoughts I had on these differences I noticed in the readings in the KJV. Any input would be appreciated!