Peace of mind has nothing to do with the external world; it has only to do with our connection with God. Love really is the answer. We're here only to teach love. When we're doing that, our souls are singing and dancing. When we remind ourselves that we are spiritual beings, that life and love are the flame eternal, that's when our soul is nourished.
There are many different kinds of prayer. Yet all prayer has one basic purpose. We pray not to get something, but to open up a two-way street between us and God so that we (and others) may inwardly become something beautiful that we share with others.