The ambassadors return and are excited that they were able to do amazing things, even the demons were frightened of them. Jesus uses this as a teachable moment and explains this is what God was pleased to do and Jesus rejoiced, full of joy. Jesus tells them:
However, do not rejoice that the spirits submit to you, but rejoice that your names are written in heaven.
Rejoice in that which is eternal, not gloating, complete joy. Now this is the definition of success.
Luke 10:17-24