Rules 4–6: instruments of grace; faith; necessity
4. Sacraments are also means or instruments through which Gospel grace is not only sealed and confirmed but truly conferred and applied to believers—baptism to regeneration (Rom. 6:4); the Supper to refresh spiritual life.
5. God Himself through the sacraments as instruments of grace exerts His power to apply and seal grace, not to any whatsoever, but only to those who apprehend what is offered by true faith. Sacraments neither have grace physically inhering nor exhibit it ex opere operato. Those who use them without faith acquire no grace and impose on themselves the heaviest burden of divine wrath (1 Cor. 11:27-29).
6. Their use is neither arbitrary nor superfluous but necessary from God's ordinance—not as simply as the preaching of the word, yet so that in a case of necessity they may be interrupted for a time. The rule: Not privation, but contempt of the sacraments damns.
Latin
4. Sacramenta sunt etiam media sive instrumenta per quae gratia Euangelii non tantum obsignatur & confirmatur, sed etiam vere confertur & applicatur credentibus. Sic Baptismus regenerationi & renovationi Spiritus inseruit (Rom. 6:4); sic per usum s. coenae vita spiritualis reficitur. 5. Deus ipse per sacramenta tanquam instrumenta gratiae virtutem suam exserit ad applicandam & obsignandam gratiam, non quibusvis, sed iis duntaxat qui oblatam vera fide apprehendunt; ac proinde sacramenta gratiam neque physice sibi inhaerentem habent, neque ex opere operato exhibent. Qui sine fide utuntur, non tantum gratiam nullam acquirunt, sed gravissimum onus irae divinae sibi imponunt (1 Cor. 11:27-29). 6. Usus sacramentorum nec arbitrarius nec supervacuus est, sed necessarius ex ordinatione Dei: non ita simpliciter ut praedicatio verbi, sed ita ut in casu necessitatis ea intermitti ad tempus possint. Regula: Non privatio, sed contemptus sacramentorum damnat.