Kloppenborg, John S. "Chapter Nine: Poverty and Piety in Matthew, James, and the Didache." in Van de Sandt, Huub & Zangenberg, Jürgen K. (editors). Matthew, James, and Didache: Three Related Documents in their Jewish and Christian Settings." Atlanta, GA: Society of Biblical Literature, 2008, 201-232.
Kloppenborg observes that poverty and piety were often associated with each other prior to the first century, and that in a way the poor were considered recipients of God's special favor, which supported them in their trials (Kloppenborg 2008,201). They, after all, were the humble before God. By that token, all who humbled themselves before God could be considered as the poor, and thus be recognized as among the pious (Kloppenborg 2008,202). This has often been recognized as a correlation in James. The value expressed in James is not necessarily that of becoming economically impoverished, but of adopting the humility characteristic of poor people (Kloppenborg 2008, 204).
Just treatment, and generous care for the poor is a common theme in biblical and other ancient Near Eastern writings (Kloppenborg 2008, 205). Care for the poor is a positive value, which sets wisdom apart from foolishness. Poverty itself is not a mark of wisdom, though it does place one into a position of receiving God's care (Kloppenborg 2008, 206). Kloppenborg notes that while poverty was not considered a virtue, the piety which was often found to accompany poverty was considered exemplary (Kloppenborg 2008, 208). The actual definition of "poor" is challenging, as Kloppenborg illustrates. Scholarly opinion is uncertain what financial criteria may have been in mind when "the poor" are discussed in biblical texts. Piety, however, was normally viewed in internal terms, not related to income or assets (Kloppenborg 2008, 211).
The relationship of poverty and piety continues in later Jewish literature. Kloppenborg illustrates the relationship with citations from the Qumran literature (Kloppenborg 2008, 214ff).
Kloppenborg notes the difficulty in distinguishing among words for poverty, as a variety of words appear in Matthew, James, and the Didache (Kloppenborg 2008, 216-217). Kloppenborg approaches the issue by considering that the words are essentially synonymous but that in general there are more and less severe levels of poverty indicated (Kloppenborg 2008, 218). He does not find a clear connection between poverty and piety in the Didache, except that charity to the poor is considered an act of piety. The poor become pious as they receive Christian instruction, not as a result of their poverty (Kloppenborg 2008, 222).
As with the Didache, Kloppenborg finds Matthew's concern for the poor to indicate they should receive charitable care (Kloppenborg 2008, 222). This charity is a means by which God's favor may be passed on to the poor (Kloppenborg 2008, 223).
Likewise, James is concerned with the poor, but Kloppenborg does not find his description to suggest an inherent piety. Rather, it suggests a humility which would dispose them to receive teaching (Kloppenborg 2008, 225-226). The pious could be rich or poor, but must be of a humble spirit (Kloppenborg 2008, 228).