Catholic sacramental theology holds that the seven sacraments actually convey grace rather than merely signifying it — the technical phrase is ex opere operato, meaning the sacrament works by virtue of the act rather than the worthiness of the minister, which was settled in the Donatist controversy. This is the deep structure behind most Catholic-Protestant differences: if grace comes through concrete channels administered by the church, then the church's role is constitutive rather than instrumental.