Grace to you and peace from God our Father and from our Lord and Savior, Jesus Christ. Amen.
What is temptation? Temptation is anything that causes you to doubt that you are a child of God. Your baptism declares that you are a child of God. At the baptism of Jesus, the Father declared the same thing of Jesus: "This is my beloved Son." So the devil comes along and tries to convince Jesus that He's not God's Son. After all, God’s Son wouldn't have to go hungry after forty days. He could just turn stones into bread. God’s Son could jump off the temple and let the angels catch Him. The Son of God could kneel, just this once, to get all the kingdoms of the world back from Satan. But Jesus clings to the Word of God. The Word declares that He is the Son. The Father said so. Jesus knows it and believes it. He trusts the Father, and He holds fast to God's Word. He drives the devil away. But none of this happens for His own sake. Jesus undergoes these temptations so that you don’t have to question whether you are God's child.
You are baptized. When the water and the Word was poured upon you, the Lord Himself says, "This is my beloved Son!" All that Jesus the Son has becomes yours at that moment. Every right and privilege and honor of being the very Son of God becomes yours. From that moment the devil will stop at nothing to cause you to doubt it, to deny it, to ignore it, to not believe it. Satan whispers in your ear: "Are you really a child of God? If you were, you would give up that favorite sin of yours. If you were a child of God, you would stop holding that grudge. If you really were a child of God, you'd act like it instead of being the selfish person you. Oh, you don't do any of that? Well just bow down by telling me how good you really are and I'll be more than happy to tell you that you're God's child!" So the devil lies and tempts and accuses. His one desire is to declare to you that you are not God's child. You are nothing but sin and death. But by the power of your baptism you can reply, "Listen, Satan. You can say all you want. But I am a baptized son of God. I am a child of God because Jesus is the Son of God. And if you want to tell me I am not God's child, you have to first prove that He is not the Son of God."
Everything that goes on in the wilderness? Jesus does that for you. He overcomes temptation for you. He does not give in to doubt for you. He doesn't believe the devil's lies for you. But that is not where the defeat ultimately happens. Jesus is the Son of God most clearly, most powerfully, when He obeys his Father's will by being arrested, condemned, and crucified. He is the Son of God the most when the Father acts most as if He's not. He is most plainly and profoundly the Son of God when He hangs on the cross in your place: in the place of every sinner, each of us who are born orphans and enemies of God. And on that Good Friday, the Lord who went toe-to-toe with Satan in the wilderness, declares, "It is finished!" Temptation is overcome once and for all. The devil can no longer question whether you are God's child since the Son of God gave His life to make you just that. Now then whenever the evil one comes calling, to try to lie to you, to make you doubt, to make you uncertain—then you simply throw your baptism in his face. You rub the words of absolution in His ear. You open your mouth for him to see the body and blood of Christ on your tongue. With those gifts of Christ, backed up by His own death and resurrection and His being the Son of God, you can proclaim, "Away from me, Satan!" And he must run away, for the Father has claimed you as His very own, and Jesus won't let anything undo that. In the name of the Father and of the Son (+) and of the Holy Spirit. Amen.
The peace of God which passes all understanding will keep your hearts and minds in Christ Jesus always. Amen.