This article offers an exegetical-theological analysis of Rom. 4:20: 'No distrust made him waver (diakr0nesqai) concerning the promise of God' (NRSV). It challenges the common assumption that our customary descriptions and definitions of 'doubt' may be applied-via negativa-to the attitude or disposition of Abraham. When Paul uses the word diakr0nesqai in this context, he does not intend to say that Abraham's disposition was free from doubt, uncertainty, or hesitation. Rather, Paul had in mind that Abraham did not oppose God in a presumptuous attitude, offend him through conceited enquiries, or question him in order to overturn his word. This interpretation counters the exegetical communis opinio, but has veritable precursors-John Chrysostom, John Calvin, and Markus Barth-and, at the same time, conforms well to the line of thought of Paul's letter. The object of Paul's accusation against Greeks and Jews (Romans 1-3) is less an intrapersonal contradiction or inconsistency rather than an interpersonal conflict between God and human being. Significantly, the contextual argument is supported by a lexicographical fact: The meaning 'to doubt' for diakr0nesqai is unattested prior to the New Testament; in classical/Hellenistic Greek the verb comprises, inter alia, the notions of 'separation' and 'dispute'.