Paul's Blessed "But Now"

Oh that blessed "but now" of Rom. 3:21! Here's Doug Moo's redemptive-historical understanding of it, surely right on:

The phrase could have a purely logical force—"but now here is the situation apart from the law"—but is more likely to preserve its normal temporal meaning. As in Rom.6:22; 7:6; 1 Cor. 15:20; Eph. 2:13; and Col. 1:22, "but now" marks the shift in Paul's focus from the old era of sin's domination to the new era of salvation. This contrast between two eras in salvation history is one of Paul's most basic theological conceptions, providing the framework for many of his key ideas. Rom. 1:18-3:20 has sketched the spiritual state of those who belong to the old era: justly condemned, helpless in the power of sin, powerless to escape God's wrath. "But now" God has intervened to inaugurate a new era, and all who respond in faith . . . will be transferred into it from the old era. No wonder Lloyd-Jones can exclaim, "there are no more wonderful words in the whole of Scripture than just these two words, 'But now.'"

—The Epistle to the Romans, p. 221.