In the passage "The Djinn Who Lives Between Night and Day" the theme is sometimes it's okay to lie if it's for a good thing, but if it's for a bad thing it's bad to lie. 

Tayab lies to the woman saying if she goes to the sea and stays there her children will come back to life, but she can never go look for them, because if she finds one they will all die. This lie was for a good thing because it gave the woman hope, but also bad because she would stay there her whole life believing a lie.

This can be tied into real life because if you lie in order to keep hope, the lie is worth telling, but if you lie and something bad can happen out of the lie, it's not worth telling.