The last post made it very clear that baptism is not limited to a one-time event. People can be baptized multiple times. You might be tempted to think that additional baptisms would only be required when something very important happens, like the start of a new dispensation. After all, it is certain that a new baptism was required when Christ was on the Earth during His mortal ministry. JST Matthew 9:18-21 says:
18 Then said the Pharisees unto him, Why will ye not receive us with our baptism, seeing we keep the whole law?
19 But Jesus said unto them, Ye keep not the law. If ye had kept the law, ye would have received me, for I am he who gave the law.
20 I receive not you with your baptism, because it profiteth you nothing.
21 For when that which is new is come, the old is ready to be put away.
But you will soon see that multiple baptisms do not require a world-changing event like a visit from Christ or a dispensation opened by Him. Alma 5 contains a discourse that Alma delivered to the church in Zarahemla. At the end of that discourse Alma says something that might seem peculiar. Verse 62 says, “I speak by way of command unto you that belong to the church; and unto those who do not belong to the church I speak by way of invitation, saying: Come and be baptized unto repentance, that ye also may be partakers of the fruit of the tree of life.” This should make it very clear to you that repeated baptisms is part of the Doctrine of Christ.