Revelation 12:11a And they have defeated him by the blood of the Lamb and by their testimony.
We can never defeat Satan without Jesus dieing on the cross for our sins and us accepting that. But look here what is next they defeated Satan by their testimony!! Our testimony gives us power over Satan. What God has done in our lives, and what God is doing in our lives has a might, mighty power when we live by God and when we share all that God has done in our lives. Not only is it powerful to the people we share with, it is powerful to our lives as well. It is a reminder of where we were and where God put us. When we tell "our story" we remember how far God has brought us.... and then we know how much further He can take us still. Every time we tell our testimony it is one more arrow in the heart of Satan! Tell you story!