Our Lutheran friends sometimes don’t play nice at recess. They like to play “gotcha” with their Reformed classmates. They tease, “Johnny, Johnny, you believe Jesus died to save the elect. How do you know you’re elect? How do you know you’re saved? How do you know Jesus died for YOU?” They try to make Johnny cry and doubt his salvation. That’s pretty mean, you Lutheran bullies, you! These Lutheran meanies want to trap Johnny into saying that if Jesus didn’t die for all, then you can’t know that He died for you. Well, that’s just not nice. Nor is it true.
Johnny could be mean in return, but momma taught him to play nice. He could say, “How do you know you won’t fall away from faith? Maybe your faith is only temporary. Jesus died for all, you say, but you still might fall away. Where’s the assurance in that?” But Johnny holds his tongue.
Instead, Johnny remembers something Martin Luther said. And something John Calvin said. They both spoke of election and assurance. And they both agreed on where to look for assurance of salvation. In playground parlance, “Luther & Calvin, sittin’ in a tree, agreed on this point of the-o-lo-gy.” Well, maybe that doesn’t work so well as a playground song.
Anyway, Luther recalled his own struggles with whether or not he was elect, during his time in the Augustinian order. Thankfully, he had a wise and gracious Father-confessor, Staupitz. Luther wrote, “Listen to the incarnate Son, and predestination will present itself of its own accord. Staupitz used to comfort me with these words: ‘Why do you torture yourself with these speculations? Look at the wounds of Christ and at the blood that was shed for you. From these predestination will shine. Consequently, one must listen to the Son of God, who was sent into the flesh and appeared to destroy the work of the devil (1 John 3:8) and to make you sure about predestination. And for this reason He says to you: “You are My sheep because you hear My voice” (cf. John 10:27). “No one shall snatch you out of My hands”’ (cf. v. 28).”
Luther heeded Staupitz’s counsel. He no longer tried to peer into God’s eternal decree. Nor did he try to look within for assurance. He looked to the incarnate, crucified Christ for assurance of his salvation – and thereby, his predestination. He heard his Savior’s voice in the Gospel, and followed Him in faith. And so he was assured he was one of Christ’s sheep, and would never be snatched from His hand.
What about Calvin? “…let us not seek (like so many) to penetrate as far as heaven and to enquire what God, from His eternity, has decided to do with us – and all this with a view to confirming the certainty of our salvation. Such a quest can serve only to stir up miserable anguish and upset in us. Rather, let us be content with the testimony by which He has sufficiently and amply assured us of this certainty. It is in Christ that all those who have been preordained to life have been elected… Similarly, it is in Christ that the pledge of our election is presented to us, if we receive and embrace Him by faith. For what are we looking for in election, if it is not that we might be partakers of eternal life? And we have this life in Christ, He who was Life from the beginning, and who is set before us as Life, so that all who believe in Him should not perish but enjoy eternal life (John 3:16). In possessing Christ by faith, we also possess eternal life in Him. This being so, we have no reason to enquire any further concerning the eternal counsel of God. For Christ is not only a mirror by which the will of God is presented to us, but He is a pledge by which it is sealed to us and endorsed.” 
OK. So maybe it took Calvin a few more words. But he drew the same conclusion from Scripture as Luther. Assurance is not found by trying to peer into God’s decree. Nor is it found by an internal examination. Rather, it is found by looking to Christ in faith. Christ is the mirror of God’s will for the salvation of sinners. Faith sees Christ crucified “for ME.” Faith embraces Christ for eternal life.
Luther & Calvin agree (although they would never go so far as K-I-S-S-I-N-G). Assurance of salvation, assurance of election, must be centered on Christ alone. Christ incarnate and crucified for sinners is the mirror and pledge of our election. This is the way of assurance for Johnny and all Christians. As you listen to the Gospel preached, you hear the voice of your Good Shepherd who laid down His life for His sheep – and you follow Him. As you look to Christ by faith, you see yourself chosen in Him from before the foundation of the world.
Martin Luther, vol. 5, Luther’s Works, Vol. 5 : Lectures on Genesis: Chapters 26-30, ed. Jaroslav Jan Pelikan, Hilton C. Oswald and Helmut T. Lehmann, Luther’s Works, 5:47 (Saint Louis: Concordia Publishing House, 1999, c1968).
 John Calvin, Truth for All Time (Carlisle, PA: Banner of Truth Trust, 2008), 45-48.