Jesus said to Peter and then to his disciples
...you do not have in mind the things of God, but the things of men...If anyone would come after me, he must deny himself and take up his cross and follow me. For whoever wants to save his life will lose it, but whoever loses his life for me will find it.
Peter had just recognized publicly that Jesus was the Messiah and the Son of the living God, but when he heard Jesus talking about suffering, death, and resurrection, he pulled Him aside to "encourage" Jesus and let Him know that no such terrible things would happen to Him. Then came the firm reprimand of "Get behind me, Satan" as Jesus recognized the temptation to avoid the crucifixion that would save the world.
Peter saw a terrible situation unfolding and thought that such tragedy would not come to one loved by God. Suffering? Death? Surely not. But the crucifixion HAD to happen in order to fulfill God's promise to keep His covenant with His people and to enable us, sinful as we are, to have an intimate relationship with Him. Peter didn't see what God saw; he didn't have in mind the things of God.
Jesus took this opportunity to teach all the disciples--not just poor, impulsive Peter--about the perspective that is needed. The life of following Jesus would not be easy. In fact, any followers would need to identify with Jesus' shameful, torturous death on the cross. Then came the paradox: losing one's life for God is saving it.
But how can that be? I want to cling to life with both hands. Deny myself? Lose my life? Surely not.
It seems backwards, and that is because I'm looking at it from the wrong perspective. Yes, I must turn over this life to God daily and follow where He leads. I need to deny my sinful self and my plans for life, give up the things of men.
Just as Peter didn't see the glorious results and the coming reign of a crucified Jesus, so it is hard for me to see the perfect plan of God. But look to the end. "Whoever loses his life for me will find it." God's perspective, the eternal one, holds so much more than I can imagine.
Lose the life I might plan, but gain a better one. The Heavenly Father offers abundant life--with meaning, power, and hardship--as I realize that He reigns. This life of mine is His. I shouldn't settle for "the things of men," but yearn for, seek out, focus on "the things of God" that last forever.
Seize eternity. It is more real and all that will last.