Ex-Opere-Operato
Sacraments confer grace by the act performed, independent of faith — the Tridentine position rejected by XXVII.3.
This is a contested or rejected alternative.
The Westminster baseline on Sacramental Efficacy is Signs-And-Seals-Conferring-Grace-By-Spirit. Personas and schools listed below hold this alternative position instead — either because they argued for it at the Assembly (like the Erastians on polity) or because they represent a receiving tradition that departed from the Standards on this point.
Cruxes on this attribute
The Assembly navigated 1 crux that bear directly on Sacramental Efficacy.
Other positions on Sacramental Efficacy
Signs-And-Seals-Conferring-Grace-By-Spirit WCF
Sacraments are signs and seals of the covenant of grace, conferring the grace signified by the work of the Spirit and the word of institution upon worthy receivers (WCF XXVII.1–3; XXVIII.6; XXIX.7).
Bare-Memorial
Sacraments are merely memorial or instructive signs with no conferral of grace — the Zwinglian position softened by Westminster's seal language.
Converting-Ordinance
The Lord's Supper functions as a converting ordinance for the morally serious unconverted — Stoddard's later position, rejected by WCF XXIX.7.