1 peter 3; 20 talks about the water of the flood. In which saved Noah, and his faily. (throught the act of Gods judgment Noah was saved or lifted up above or out of Gods judgment)
in the same way we will be saved, Which is also represented another way..
1 Peter 3: 21 speaks of another symbol (just like the water) which now saves us. Baptism.
yet he makes clear understanding that it does not remove sin from the flesh (it does not save us from sin) It is done only wiht a good conscious towards God (in obeying his commands, ie it is just like every other command God gave in which he desires us to obey) and is is really the resurrection of Christ which saves us, Which the water prefigures the death, burial and resurrection of Christ, Which truly saves us.