Contemporary English Version (CEV)
We don't know what what we know sometimes.
Caiaphas thought he had it figured out -- they would have Jesus killed to save one the country. They worried that Jesus might stir up a rebellion, and so having him killed would mean they could avoid Rome cracking down on Israel.
In reality, God prophesied through Caiaphas that Jesus, one man, would die for the sins of many. Jesus would die so that all of mankind would be saved. It's not fair, is it? Why should one man have to die for the sins of many? But God offers his son, such is his love. Jesus could have complained about how unfair it was, but instead he was obedient, sacrificially offering himself for many.
Caiaphas wasn't humble enough to realize that God might be pointing to something bigger than himself. God was at work through him, even if he wasn't aware. I think there are times in our lives when God is using us, even when we aren't aware. It's a matter of being humble and realizing that God is at work when we cannot see, and being willing to go and do just as God would have us, even if we cannot understand the full meaning.