The quote "sometimes, all it takes is one prayer to change everything "explains the soothing power of prayers and how communication between God and man could be the answer to many questions man finds himself asking. It gives us a clearer explanation of how we could find peace no matter how deep we are in despair once we decide to pray. Much more than that, prayer is a dialogue with God. We are bringing our needs, wants, and heart to him, but it is also a chance for us to listen and discern whether we are asking for the appropriate things, doing it in a the proper manner, having his best interest at heart rather then erring on the side of selfishness, etc. If we make the effort, it can become a dynamic, ever-evolving aspect of our relationship with our creator.
There is practically no limit to how prayer may change circumstances in people's life since it releases and invites the power of God into a situation. Miracles doe happen, things will get better, situations might change, you'll discover peace and hope will be restored.