At first glance, Jesus' words appear to offer his followers a path to getting whatever they want from God. Upon closer examination, this conversation fits with all the other times Jesus and the biblical authors wrote about prayer and requests from God: they need to conform to the will of God. In addition, this promise is for the people of God, not the persons of God. The people of God have one defining purpose: to be God's representatives here on earth, sharing the Gospel and making disciples. When we pray, together, confidently, for that, God hears us and will bless our work on his behalf.
Secondly, Jesus reminds us that forgiveness too needs to be done God's way, and that means forgiving others and letting go of our pride, self-righteousness, and hopes of revenge.