Which of you, if his son asks for bread, will give him a stone? Or if he asks for a fish, will give him a snake? If you, then, though you are evil, know how to give good gifts to your children, how much more will your Father in heaven give good gifts to those who ask him!
In relation to the previous two verses, here we see an illustration as to why God will answer our prayers. Probably one of the most important concepts here is that God is good. He is going to give us what is good.