Romans 3:22 is a condensate of the Apostle Paul’s gospel; he compresses Christianity into this eleven-word construction: δικαιοσύνη δὲ θεοῦ διὰ πίστεως Ἰησοῦ Χριστοῦ εἰς πάντας τοὺς πιστεύοντας “God’s righteousness through faith in Jesus Christ for all who believe”
Romans 3:22 shows that faith is central in Christianity. Faith is also mysterious because God is both the giver and pursuer of faith. We cannot arouse faith in ourselves whenever we want to. We are only enabled by the work of the Spirit to “accept, receive, and rest upon Christ alone for justification, sanctification, and eternal life” (Westminster Confession 14.1). But at the same time, as the author of Hebrews says, God seeks and requires faith in us; we cannot please God without faith (11:6). Kierkegaard, too, holds that God can only be known by a leap of faith.
Although some scholars attempt to re-define faith (πίστις) as something like “allegiance” (e.g., Matthew Bates, etc.), I find no linguistic evidence for such a rendering. Allegiance, loyalty, or obedience is all the result of salvation by faith alone in Christ alone (cf. Charles Spurgeon). Faith, therefore, is, most of all, personal belief in “whatsoever is revealed in the Word” (Westminster Confession 14.2).
This mysterious centrality of faith challenges humanity’s narcissistic self-centered illness. Barrett, in his 1957 commentary on Romans, rightly points out that our “basic ill” is that we worship ourselves (“the idolatry of self,” p. 81). So I cannot agree with him more when he writes, “the cure of this ill is faith” (81).