The power in the name of Jesus

Today most Christians usually end their prayers something like this “In the name of Jesus, Amen!”. But the name of Jesus is not some kind of magical formula, and do we really understand what we are saying when we use the name of Jesus in prayer? The name of Jesus is a powerful name that can make the gates of Hell tremble and demons run away with the tail between their legs — but what makes the name of Jesus so powerful?