Question

manners make character

Answer 1

manners make character change in passive voice

Answer 2

in active voice, the subject is doing the action:

the dog ate the cheese.
nancy ate her dinner
the wind knocked down the tree
manners make character

in passive voice the subject stops doing the things and becomes the passive object of the action:

the cheese was eaten by the dog
her dinner was eaten by nancy
the tree was knocked down by the wind
character is made by manners

Answer 3

Not necessarily, as there are other factors that make character, but manners is surely one of them.