Why did Paul cite Habakkuk 2:4b?

One of the most perplexing uses of the Old Testament in the New is Paul’s quotation of ‘the one who is righteous will live by faith’ to support his view that: divine righteousness is revealed through faith (Rom 1:17); no one is justified before God by the law (Gal 3:11); and no one is justified by the works of the law but through faith in Jesus Christ (Gal 2:16). Why did Paul quote Hab 2:4b, since this half-verse is not ostensibly about judgment and salvation? In this article, I show that Paul’s selection is explicable when it is realized that there was a Jewish tradition, as reflected in Pesher Habakkuk (1QpHab), which interpreted righteousness and living by faith as salvation for the righteous and judgment for the wicked.