Grace, mercy, and peace to you from God our Father and the Lord Jesus Christ! Amen. In the days before caller ID, did you ever have this experience: somebody called you on the phone, and even though they clearly knew who you were, because they didn’t give their name, you didn’t have a clue who they were? Some people have a really hard time recognizing voices. Whenever a new song by one of our favorite singers or bands comes on the radio, I instantly recognize who the singer is because of their familiar voice. Lisa can’t do this. She will get Katy Perry and Taylor Swift mixed up. She can’t tell the difference between Sara Bareilles and Ingrid Michaelson. Coldplay and the Fray sound the same to her. I often have fun at her expense by quizzing her on whether or not she can figure it out. Thankfully, for people like Lisa, now you can ask your phone, “Okay, Google, what song is this?” And after listening for about 15-20 seconds, you’ll have your answer.
But there is a very small percentage of the population who actually have a neurological disorder called phonagnosia. It’s the complete inability to recognize even familiar voices. Such patients may be able to match musical pitch, but they still can’t tell the difference between a celebrity’s voice and that of one of their family members or close friends. One woman with this condition reported great distress that on the playground she couldn’t tell the difference between her child’s cry and those of other children. How would she know if something were wrong?
Some people suffer from what you might describe as a spiritual form of phonagnosia. They don’t recognize the voice of Jesus the Good Shepherd. In our Gospel lesson, Jesus tells his opponents, “You do not believe because you are not part of my flock. My sheep hear my voice, and I know them, and they follow me” (John 10:26-27, ESV). People who reject Jesus and his Word fail to recognize the divine character of what he says. But Jesus’ sheep recognize his voice. They know the difference between the voice of Jesus and that of a stranger. “A stranger they will not follow, but they will flee form him, for they do not know the voice of strangers” (v. 5).
Yet strangers do come and try to break in among the fold. Jesus warns, “For many will come in my name, saying, ‘I am the Christ,’ and they will lead many astray” (Matt. 24:5). Others come claiming to be from God, but the pernicious doctrines they teach are deadly dangerous. That is why, in his farewell address to the Ephesian pastors (“elders”), the Apostle Paul said:
“Pay careful attention to yourselves and to all the flock, in which the Holy Spirit has made you overseers, to care for the church of God…. I know that after my departure fierce wolves will come in among you, not sparing the flock; and from among your own selves will arise men speaking twisted things, to draw away the disciples after them. Therefore, be alert…” (Acts 20:28-31a).

As I’ve said before, you don’t warn people about non-existent threats. The danger of false prophets and false teachers is very real, which is why, in another place, Paul writes, “But even if we or an angel from heaven should preach to you a gospel contrary to the one we preached to you, let him be accursed” (Gal. 1:8).
That is the way of death and damnation. There are many different voices clamoring for our attention in the world today: talking heads on TV, talk radio, Internet blogs, news websites, social media, and sometimes (still) even plain old newspapers and books! But as the sheep of God’s flock, we should never listen to the voice of another shepherd—a false shepherd, who is really a wolf in sheep’s clothing trying to break in to kill and destroy our faith or steal our hearts away from Jesus. “Pay careful attention,” Paul warns. “Be alert…” (Acts 20:28, 31).
Jesus the Good Shepherd gently reminds us: “My sheep hear my voice, and I know them, and they follow me” (John 10:27). But how do we recognize Jesus’ voice? How do we know what he sounds like? After all, Jesus lived 2,000 years ago, long before recording equipment. You can’t listen a CD or mp3 of Jesus’ voice.
Yet there remains one place where the voice of the Good Shepherd is unmistakable: in the Holy Scriptures. The Bible contains all of God’s commands and promises. And every word of Scripture points to Christ. Martin Luther once said that if you could cut the Bible with a knife, it would bleed Christ. Jesus himself says the same throughout the Gospels (cf. John 5:39). “Beginning Moses and all the Prophets, he interpreted to [his disciples] in all the Scripture the things concerning himself” (Luke 24:27). So if you want to hear the voice of the Shepherd, study your Bible and listen to good preaching. Remember: “Faith comes by hearing…” (Rom. 10:17). By not hearing regularly, your faith can be taken away. Listen instead to Jesus and follow him.
Yet even as our Shepherd takes the lead and guides us through the valley of the shadow of death on the road to the cross, danger still arises. Temptation most often comes when we’re not expecting it. False teaching can have just enough ring of truth to trick us. No matter how many Bible verses we memorize, no matter how many worship services or Bible studies we attend, we still sin and come up short. “All we like sheep have gone astray; we have turned—every one—to his own way,” writes the prophet Isaiah.
But the Good News is that “the LORD has laid on [Jesus] the iniquity of us all” (Isa. 53:6). Christ bore our sin to the cross. And because he bled in our stead, God forgives us and gives us eternal life. We belong to Jesus now—not the devil, not the world, not even ourselves. We belong to Jesus. “For he is our God, and we are the people of his pasture, and the sheep of his hand…” (Ps. 95:7a). Now nothing and no one can snatch us out of Jesus’ hand (John 10:28). The heavenly Father has given us to Jesus. And nobody can snatch us out of the Father’s hand either (v. 29). For Jesus and the Father “are one” (v. 30).
But there are other sheep who are not yet part of Jesus’ flock, people who don’t believe in Jesus—at least not yet! “I must bring them also,” Jesus says, “and they will listen to my voice. So there will be one flock, one shepherd” (John 10:16). Christ came to save the whole world. He came “to seek and save the lost” (Luke 19:10). He leaves the 99 on the hillside to go in search of that one lost sheep, including your unbelieving friends, family, coworkers, neighbors, and classmates. Jesus laid down his life for the sheep, and he took it up again when he rose from the dead on the third day. He came to give abundant life, eternal life, life without end. So we bleat and beckon for others to join the flock, to follow Jesus, to listen to his voice.
“The sheep hear his voice, and he calls his own sheep by name and leads them out” (John 10:3). Today the Good Shepherd calls to you. Do you hear his voice? Will you follow him on paths of righteousness for his name’s sake (cf. Ps. 23:3)? At the end of time, the Lord will separate the sheep from the goats (Matthew 25). Don’t be a goat! Jesus wants you to be his sheep. Won’t you let him be your Shepherd? In the name of Jesus. Amen. Alleluia! Christ is risen! He is risen indeed! Alleluia! Amen.