"He that believeth and is baptized shall be saved" (Mark 16:16a).
Among the Lutherans, this text is still appealed to, front and center, in support of baptism, as happened to an infant at the opening of a recent church service. This habit of citation is infelicitous, because the text comes from the long ending of Mark, which is not penned by the same person who wrote up through Mark 16:8. To go on quoting from this long ending simply will not do. It diverts the attention away from the topic at hand.
Whole academic careers have been made out of this problem of the ending of Mark. Suffice it to say that the internal and external evidence of the verses after vs. 8 have convinced all but the most stubborn defenders of the Textus Receptus that they were supplied, albeit from an early date. Why were they supplied? Because the want of an ending was felt. To end the Gospel in fear and in silence without a resurrection appearance in Galilee, as promised, just wouldn't do.
So what happened? There have been many proposals, of course, and we will probably never really know. Perhaps "Mark" never finished his work. But to suggest, as some have, that he intended to end there at vs. 8 for literary reasons just sounds crazy. Most of the New Testament was rightly dismissed as "Kleinliteratur" a long time ago. And that's being generous to Mark. I prefer to think his original got damaged, obviously at a very early date. The mucked up ending is just one of its many inadequacies which went on to be answered by Matthew, Luke and John.
As for texts to be read in support of baptism, especially infants, I nominate the stories in Acts 16, where Lydia, a seller of purple, believed and was baptized, "and her household" (vs. 15), and where the jailor was baptized, "he and all his, straightway" (vs. 33). Whether or not it is conceivable that infants can be inferred from the language, the concept of inclusiveness certainly shines forth, as in "Suffer little children, and forbid them not, to come unto me: for of such is the kingdom of heaven" (Mt. 19:14).
