One of the ways that texts explore ideas is to throw opposing themes together, in order to highlight the contrast between different characters. To see this, look at how they are described and see if their words match their actions. Think about whether the reader is supposed to be sympathetic to the character (are they likable?) or unsympathetic (not likeable).
One of the key things to remember is to listen to the dialogue of the characters. Look at what they say and see how different characters reveal themselves through their speech – each character will have their own idiolect that is unique to them.