1 John 4:15

And if we know (for a fact, as indeed we do) that He hears and listens to us in whatever we ask, we know (with settled and absolute knowledge) that we have (granted to us) the requests which we have asked from Him.  

Our faith begins when the prayer ends. We pray to God according to His will and the word for our requests. God hears our prayers, and we stand in faith for our answer. We are removing any doubts from our minds and walking in peace that He has heard.