Complex sentence: Besides his "Commentaries on Sacred Scripture" and his "Sermons", Bonaventure has written works of pure spirituality in strict dependence and vital application, because he felt that all knowledge that is not founded on Christ is vain.
Split into simpler sentences: Besides his "Commentaries on Sacred Scripture" and his "Sermons", Bonaventure has written works of pure spirituality. They are in strict dependence and vital application because he felt that all knowledge that is not founded on Christ is vain.