When He made that statement about not losing one, He was clearly talking about the apostles.   It is you with your predestination nonsense that says Jesus died in vain.   You are saying that Jesus's atoning blood is only available for a select few, while I am saying that it is available for ALL.
2nd Corinithians 5:15 And he died for all, that those who live should no longer live for themselves but for him who died for them and was raised again.
So is the blood of Jesus for all or just a select few?
John 1:29, "The next day he saw Jesus coming to him, and said, 'Behold, the Lamb of God who takes away the sin of the world!'