Ananias and Sapphira saw Barnabas' example (Acts 4:36-37) and wanted to get the same notoriety for themselves without the level of commitment that Barnabas showed. The notoriety doesn't belong to Barnabas, though, and they didn't seem to understand that. They weren't just stealing money from God, but honor. That, combined with their proximity to the center of The Way, served as a lightning rod for God's wrath.
Acts 5:1-11