This verse is the minimal definition of the “fruit meet” for baptism. The “broken heart and a contrite spirit” is an allusion to Psalms 34:18: “The Lord is nigh unto them that are of a broken heart; and saveth such as be of a contrite spirit.”
Associating this psalm with the baptismal condition is particularly appropriate. The unrepentant person who declines baptism is necessarily defined as the natural man, who is “an enemy to God, and has been from the fall of Adam, and will be, forever and ever, unless he yields to the enticings of the Holy Spirit, and putteth off the natural man and becometh a saint through the atonement of Christ the Lord” (Mosiah 3:19). Accepting the Messiah’s atonement occurs in the ordinance of baptism. Thus, when one is qualified for baptism and accepts that ordinance, the natural man is put away, and the person literally is more “nigh” to God.
Another implication of the need to bring forth worthy fruit to qualify for baptism is that one must learn the gospel prior to baptism. Otherwise, one cannot understand what “fruits” should be brought to baptism. While Moroni does not describe a prebaptism catechism, it is well known from the Old World baptismal rites. Bradshaw describes the evidence from Syrian practice:
There are strong indications that initiation was once a two-stage affair in Syria, with the profession of faith, in the form of an act of adherence to Christ or syntaxis (preceded by a renunciation of evil, if that is not a later development), taking place on a separate occasion prior to the baptism. The primary evidence of this is provided by the Didascalia [a Syrian text dated to between A.D. 200–250], which says that “when the heathen desire and promise to repent, saying ‘We believe,’ we receive them into the congregation so that they may hear the word, but do not receive them into communion until they receive the seal and are fully initiated.” Although it may seem odd that converts were expected to express their faith before they were allowed to hear the word, what is meant here seems to be that, while there would have been some preliminary moral instruction designed to bring them to repentance and faith, certain teachings were reserved until after they had made their expression of commitment to Christ. Although this final pre-baptismal instruction disappeared in the fourth century, being replaced by post-baptismal mystagogy, its earlier existence is confirmed both by evidence of comparable practice in other regions… , and by the persistence of at least a short interval between the profession of faith and the baptism itself in later Syrian rites: John Chrysostom in the late fourth century and the Constantinopolitan rite of the fifth century seem to have known the renunciation and act of adherence as still occurring the day before the baptism.
Generalizing, Bradshaw notes: “What can be said to have emerged as common to rites by the time that the third century is reached, out of the apparent diversity of practice of earlier times, are certain fundamental ritual elements—preparatory instruction, renunciation and act of faith, anointing, immersion, and perhaps also imposition of hands—but each of these still tends to take a different form and, at least to some extent, a different meaning in the various local or regional traditions.”