The Judeo-Christian heritage includes the concept of building a more just and equal world (Sider, 1977; Santa Ana, 1979). The faithful are expected to identify with the poor; sacrifice some of what they have for those who have less; challenge policies and practices that foster injustice and inequality; and as Sider (1977:87) put it, "develop communities based on an entirely new set of personal, social, and economic relationships." These new relationships are symbolized by biblical practices such as a jubilee year every fiftieth year, at which time all land was to be returned to its original owners; a sabbatical year every seventh year, during which the fields would lie fallow and replenish themselves, slaves could gain their freedom, and all debts would be cancelled; a practice of setting aside 10 percent of all crops every year and every three years distributing the accumulated crops among the poor; a practice of leaving some crops in the fields for the poor to glean; setting aside a Sabbath day so all workers could rest; no charging of interest on loans; and common ownership of all goods. Sider (1977:95) says Christians are challenged "to discover the underlying principles" of these practices and "search for contemporary strategies to give flesh to these basic principles."