The next words in this verse are: "The Good Shepherd sacrifices His life for His sheep.
The whole first half of this chapter of John Jesus talks about the Good Shepherd.
What's interesting to me that Jesus contrasts the way He cares for us - His sheep - not with the opposite with the shepherd ... which ... I'd think would be the butcher. Jesus gives us life - the butcher would be the one who'd take a sheep's life away. Instead - Jesus contrasts Himself with the thief.
Of course - when we don't accept the abundance that Jesus offers - we don't die - we just end up living an existence with the best parts stolen from us - the parts that the thief sneakily snuck in and stole.
Sometimes the thief looks like fear. Sometimes it looks like sucking up. Sometimes it looks like a whole lot of religiosity. Honestly - the thief is totally a black-belt ninja chameleon. Actually - we are so vulnerable to having the abundant life Jesus wants to give us taken away from us - that it takes a fair bit of courage and a lot of Jesus' love to help us hang onto what Jesus offers. It's easier to live stolen from than it is to walk by faith in Jesus' love - but only for a moment. Jesus' way is not only the abundant life - but it's the only life that feels like living. Jesus' way offers us freedom. The thief - in the end - really is in cahoots with the butcher.