 He and Eulogius made it part of their lives’ works to preserve Latin-Christian culture despite it becoming eroded by the ruling Muslim culture; in particular Alvarus saw the gradual replacement of Latin as the language of high culture and learning with Arabic as a problem he had to correct.One method of achieving this goal was to import Latin literature from the North into the South of Spain, such as Augustine's "City of God" which would not have been a rare volume under Christian rule.Alvarus, Eulogius, and earlier their mutual teacher Speraindeo were the first Iberian Christians who systematically and theologically attacked Islam in their writings.