Such questions have been with humanity for a long time and are forever relevant to our human condition. At the very beginning, Adam and Eve heard both the voice of God and that of the devil, the voice of truth and the voice of falsehood. They chose to listen to the lie, a decision with terrible consequences for the subsequent history of humanity. Ever since then we have had to discern carefully among the voices competing for our attention as we make our life-determining decisions.
The problem is particularly acute in our day. Television, Internet, social media and so on bombard us daily with their messages, some good, many not. To whom do we listen? What is right? What is wrong? How do I know the difference? The problem is compounded in our Western society, with its moral relativism. Truth is not an objective norm to which I conform my life, but something that I determine myself. Nature is not a prior given that establishes parameters to behaviour, but whatever I declare it to be so that all boundaries to desire are removed. I need listen to no voice other than my own, since I myself can determine what is good and what is evil. Adam and Eve revisited.
In the midst of this dark confusion, we hear from the Gospel a voice speak with great clarity. "My sheep hear my voice." (John 10:27) This is the voice of Jesus. He is identifying himself as the shepherd, who is sent to find and lead us, his sheep. We know the path to take, we correctly discern between right and wrong, we leave the wilderness of confusion and anxiety to arrive at pastures of clarity and peace, when from among the multiplicity of voices we listen to one, and one only: that of Jesus. "My sheep hear my voice," not that of another.
We listen to him exclusively because he is not just any shepherd; he is the Good Shepherd, something he demonstrated to us in many ways. He is the Good Shepherd because he is divine, he is the Good itself. He is Good because he, the Son of God, descended from heaven to assume our human nature and lead us. He is Good because he came in search of the lost sheep, us, ready to leave the ninety-nine secure ones to find the one who was lost and in danger. Finally, he is the Good Shepherd because he is ready and willing to lay down his life for his sheep. Unlike the shepherd who will run from ravenous beasts and leave the sheep to their fate, this Shepherd actually takes the place of the sheep and dies in their stead. In so doing he saves us from the jaws not of wild animals but of Satan himself, whose power was destroyed when the Shepherd-turned-Lamb offered his life on the Cross. The Good Shepherd became the Paschal Lamb who by dying and rising gave life, eternal life, to his sheep. As we learn from Revelation, this Lamb, Jesus the risen Lord, now reigns in heaven and is worshipped by the heavenly multitudes. This is why we listen to the voice of Jesus, our Shepherd. This is why we listen only to him. Only he shows us the way to peace in this life and to eternal joy in the next.