“God’s covenant justice comes into operation through the faithfulness of Jesus the Messiah, for the benefit of all who have faith” (Romans 3:22 KNT).  In the NT the “faith of Jesus” is really better translated “the faithfulness of Jesus”, as in this translation.  Notice it says, “for the benefit of all who have faith”.  Our faith joined to His faithfulness is saving faith.  Living the New Covenant in faith means that we seek to be faithful to God in the same way Jesus has been faithful to us.  Faithfulness is the proof of faith’s presence.