In other words, they were the Buddhism under the Ritsuryo system; the priests of these sects were just scholars studying Buddhism under the protection of the nation, and as for actual religious activity, they just performed some magical prayers for the idea of Chingo-Kokka (guarding the nation by Buddhism).
つまり、律令体制下の仏教で国家の庇護を受けて仏教の研究を行い、宗教上の実践行為は鎮護国家という理念の下で呪術的な祈祷を行う程度であったといわれる。