Romans 1:17

For therein is the righteousness of God revealed--that is (as the whole argument of the Epistle shows), GOD'S JUSTIFYING RIGHTEOUSNESS. from faith to faith--a difficult clause. Most interpreters (judging from the sense of such phrases elsewhere) take it to mean, "from one degree of faith to another." But this agrees ill with the apostle's design, which has nothing to do with the progressive stages of faith, but solely with faith itself as the appointed way of receiving God's "righteousness." We prefer, therefore, to understand it thus: "The righteousness of God is in the gospel message, revealed (to be) from (or 'by') faith to (or 'for') faith," that is, "in order to be by faith received." (So substantially, MELVILLE, MEYER, STUART, BLOOMFIELD, &c.). as it is written-- (Hab 2:4). The just shall live by faith--This golden maxim of the Old Testament is thrice quoted in the New Testament--here; Gal 3:11; Heb 10:38 --showing that the gospel way of "LIFE BY FAITH," so far from disturbing, only continued and developed the ancient method.

— Jamieson-Fausset-Brown Commentary (public domain)