Imagine for a brief moment if these 16 words were contained in the Bible. Imagine how the entire history of Christian theology would have been changed by such a simple phrase. How many arguments have dealt with baptism by immersion? How many missionaries have spent far too long discussing the importance and symbolism of immersion in the technique of baptism? If only the Bible had this phrase, then there would have been no disputations.
The Book of Mormon was given for the confounding of false doctrines and laying down of contentions, and establishing peace (2 Nephi 3:12). No single ordinance is covered as completely as is baptism. This is one ordinance about which the Lord wanted no more contention. We are taught that authority from God is necessary to perform the ordinance (v. 21). We are also taught what to say (v. 25), how to perform it (v. 26), and the doctrinal incorrectness of baptizing infants and little children (Moroni 8:5-22).
Orson Pratt
"Now, let me ask, who could draw any two conclusions from words as plain as these? No person could; and there could be no two churches differing, or built up upon the principle of baptism as here revealed. So it is in regard to every other point of doctrine relating to the plan of salvation revealed in this book; they are all just as plain as the one to which I have called your attention. Hence, when people understand, and comprehend by the power of the Holy Ghost, that this record is divine, and when they can once put their confidence in it as such, they never after that need be at a loss concerning the points of the doctrine of our Lord and Savior. 'They…that erred in spirit shall come to understanding; they that murmured shall learn doctrine.' (Isa 29:24)" (Journal of Discourses, 17:288)