The old King James translation and many new translations simply state from faith to faith in this verse. This is very vague and doesn’t give the reader a clear idea of Pauls meaning. A much clearer translation is provided below:
OLD: For therein is the righteousness of God revealed from faith to faith: as it is written, “The righteous through faith shall live”.
NEW: For therein is the righteousness of God revealed through faith, as being by faith: as it is written, “The righteous through faith shall live”.