The Large Catechism

In the same manner as we have heard regarding Holy Baptism, we must speak also concerning the other Sacrament, namely, these three points: What is it? What are its benefits? and, Who is to receive it? And all these are established by the words by which Christ has instituted it, and which every one who desires to be a Christian and go to the Sacrament should know. For it is not our intention to admit to it and to administer it to those who know not what they seek, or why they come. The words, however, are these.