For it has been granted to you that for the sake of Christ you should not only believe in him but also suffer for his sake (Phil. 1:29).
The phrase, "faith for faith," is taken directly from the translation of Rm. 1:17 by the English Standard Version, expressly, "For in it [that is, the Gospel] the righteousness of God is revealed from faith for faith." I say, "translation," but I mean more "interpretation" for, though the literal interpretation of the passage is "faith to faith," I am thinking (though I am unsure of this) that the translators of the ESV are picking up on part of what the apostle is doing with this phrase, namely using it as an inclusio to bracket with Rm. 3:21, 22 the section of the epistle from Rm. 1:18-3:20. [An "inclusio," is a literary device used to set apart a particular section of literature, bracketing it with common phrases.]
This intention by the apostle becomes quite apparent when we look at this seemingly obscure statement by the apostle in Rm. 1:17, viz. "the righteousness of God is revealed from faith for faith," in light of the clear statement by the apostle in Rm. 3:21, 22: "But now the righteousness of God has been manifested apart from the law, although the law and the prophets bear witness to it–the righteousness of God through the faith of Jesus Christ for all who [have faith]" (translation mine; compare with Young’s Literal). In other words, we see that the revelation of the Righteousness of God (which is the Gospel, mind you) is not merely transacted from God’s righteousness to human faith, but it is transacted from God’s righteousness to Christ’s faith granted to the elect manifested by their personal faith. In other words, this simple statement, "faith for faith," states what is said more explicitly elsewhere, namely that our faith is not our own but is a gift from God (cf. Eph. 2:8) and that Christ is the author and finisher of our faith (cf. Heb. 12:2). This simple phrase explains both how faith can be counted as righteousness and how dead men become alive in Christ to believe the Gospel, for even a man’s faith originates in God and in God alone. Second, in the immediate context, the phrase from Rm. 1:17: "The righteousness of God is revealed from faith for faith" stands perfectly paralleled to the subject of the discourse of the section it brackets, namely "the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men who by their unrighteousness suppress the truth" (Rm. 1:18). In other words, as becomes quite apparent in the following discourse by the apostle, there are two places in which a person can stand, and only two—either a person stands in faith and is covered in the Righteousness of Christ, or a person stands under the wrath of God which shall be poured upon that soul when the temporal propitiation of wrath afforded for that soul by the work Christ is expired. His works will on that day be rendered unto him (cf. Rm. 2:6), and he will be judged and damned in accordance to the law that has been revealed to him, either in the written code or in that which has been written upon his heart (cf. Rm. 2:12, 14-16). Therefore, the apostle can say with absolute certainty the truth which he proclaims in Rm. 2:12: "For all who have sinned without the law will also perish without the law, and all who have sinned under the law will be judged by the law." I hope that this short overview of the phrase, "faith for faith," as found in Rm. 1:17 shows that the name of this site was not chosen in vain but was chosen because the heart of the Gospel lies therein. We are nothing apart from the work of Christ, and therefore all of our boasting is excluded since we are justified by a law of faith (cf. Rm. 3:27)–a faith that comes from God alone and imputes to us a righteousness that comes from God alone. To him alone be glory forever! Amen.