Before the faith of Christ came, man had faith, but It was his own faith. Man lived by his own faith. But after the faith of Christ has come, the believer lives by the faith of Christ.
22 But the scripture hath concluded all under sin, that the promise by faith of Jesus Christ might be given to them that believe.
23 But before faith came, we were kept under the law, shut up unto the faith which should afterwards be revealed.
24 Wherefore the law was our schoolmaster to bring us unto Christ, that we might be justified by faith.
25 But after that faith is come, we are no longer under a schoolmaster.
Galatians 2:20 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.