When a new dispensation of Christ’s gospel occurs, re-baptism is required. The Jews were practicing baptism before John the Baptist. But first John, then Christ taught that re-baptism was necessary to accept God’s new work.
This is from the New Covenants, Matthew 4:10:
Then said the Pharisees unto him, Why will you not receive us with our baptism, seeing we keep the whole law? But Jesus said unto them, You keep not the law. If you had kept the law, you would have received me, for I am he that gave the law. I do not receive you with your baptism because it profits you nothing, for when that which is new has come, the old is about to be put away; for no man puts a piece of new cloth on an old garment, for that which is put in to fill it up takes from the garment, and the rent is made worse. Neither do men put new wine into old bottles, else the bottles break, and the wine runs out, and the bottles perish. But they put new wine into new bottles and both are preserved.
Joseph Smith’s edit of the passage makes it clear the topic that led to the new cloth-old garment, new wine-old bottles comparison by Christ was re-baptism.