From Core Christianity, a Reformed ministry branching from The White Horse Inn:
The sacraments are means of grace.
The sacraments are means of grace, not personal pledges of obedience. Theologian Louis Berkhof explains that the means of grace are ordinary means “by which the Holy Spirit works and confirms faith in the hearts of men” (Berkhof, Systematic Theology, 605). It is easy to think of the sacraments as things we do as a pledge of obedience to God or a sign that we’re giving our life to him. But this is to fundamentally misunderstand the nature of a sacrament. Sacraments are not things we do for God but are ordinary ways the Holy Spirit applies the benefits of salvation. In addition, it is only by faith that a person receives these benefits.
While not the means of salvation itself, the sacraments serve to really and truly nourish and sustain a Christian’s faith. It is important to note that the sacraments are signs and seals of what Jesus did, not what Jesus does to save. By themselves, being baptized and eating some bread and wine do nothing. It is when the Holy Spirit works through them and the participant has faith that the person is renewed and refreshed and has communion with Christ himself.
Notice the nuance employed here: the sacraments are “not what Jesus does to save,” but yet “the Holy Spirit works through them” to affect the faith of the recipient. I would use even stronger language than the author here did, but nevertheless, this is the Reformed, catholic religion which Jesus founded. Amen.