All the words and stories of the gospels are sacraments of a kind, sacred signs by which God works in believers what the histories signify. Just as baptism is the sacrament by which God restores us; just as absolution is the sacrament by which God forgives sins, so the words of Christ are sacraments through which he works salvation. Hence the gospel is to be taken sacramentally, that is, the words of Christ need to be meditated on as symbols through which that righteousness, power, and salvation is given which these words themselves portray…. We meditate properly on the gospel, when we do so sacramentally, for through faith the words produce what they portray. Christ was born; believe that he was born for you and you will be born again. Christ conquered death and sin; believe that he conquered them for you and you will conquer them.

Luther, Sermon for Christmas Day 1519, quoted in John Kleinig, Grace upon Grace