Redaction: When Mormon states that Alma commanded that “there should be no contention one with another, but that they should look forward with one eye, having one faith and one baptism, having their hearts knit together in unity and in love one towards another,” it is either Mormon’s synopsis of the intent of Alma’s teaching, or a direct quotation. With Mormon’s clear (and well-deserved) admiration for Alma, one would suspect that Mormon would take the opportunity to insert some of Alma’s words here. However, it is most likely a description rather than a quotation. It says what Alma said but does not replicate the precise wording.
Of course, the “one faith, one baptism” phrase echoes Ephesians 4:5: “One Lord, one faith, one baptism.” Probably, this phrasing again displays Joseph’s Smith familiarity with Paul’s writings, but the concept of communal unity resulting from baptismal covenants is completely harmonious with Alma’s context. Even though the specific wording owes a debt to Paul, the meaning is Alma’s, describing his hope for this new community.
Scripture: Mormon indicates that his people became “children of God” through the unity of their faith and baptism. Embedded in Mormon’s argument as it is, this phrase suggests that it is Mormon’s, rather than Joseph Smith’s. Mormon is summarizing the people’s conversion process, indicating that Alma’s people have undergone the great change described by Benjamin: “And now, because of the covenant which ye have made ye shall be called the children of Christ, his sons, and his daughters; for behold, this day he hath spiritually begotten you; for ye say that your hearts are changed through faith on his name; therefore, ye are born of him and have become his sons and his daughters” (Mosiah 5:7). Because the Nephites understood that Yahweh and the Messiah were the same, I see “children of God” and “children of Christ” as equivalent phrases.