From Church Society in the UK, here is a piece by Wallace Benn on Article 25 – Of the Sacraments that is worth reading. These two paragraphs say a lot:
The sacraments then are spiritual food for spiritual people. The Article adds St. Paul’s warning that unworthily received (i.e. without belief and trust in Christ’s substitutionary atoning death for us) they add to our condemnation.
The sacraments are “not only badges or tokens of Christian men’s profession” (a view associated with the continental reformer Zwingli, but I think perhaps an inadequate explanation of his teaching). Rather, they are means of encouraging and strengthening the believer’s faith generally, and particularly in times of difficulty, doubt, or despair. They are both “certain sure witnesses” that proclaim the gospel promises to us in a concrete fashion, and also “effectual signs of grace” to those who receive them with a believing heart.
There are some very good quotes by Cranmer in the piece as well – read it all.