Because They Know His Voice

When he has brought out all his own, he goes ahead of them, and the sheep follow him because they know his voice. They will not follow a stranger, but they will run from him because they do not know the voice of strangers.
John 10: 4-5 (NRSV)

When I was a freshman in college, I took a world cultures class that required reading several dense academic papers written by archaeology and anthropology scholars. When asked why college freshman should read papers written for graduate or even higher level readers, my professor explained that he wanted us to learn how to delve into complexity.

"Learn to discern truth," he said, "in a world that wants nothing more than for you to accept it at face value--a world that wants you to absorb everything it tells you without ever questioning its motivation or agenda."

This was an ominous injunction, indeed, but one that has followed me ever since.

I've often heard people say, "I don't trust that man (or woman), because I think he has an agenda." I've said it myself a few times. But to be fair, just about everyone has an agenda. Everyone has a set of goals or perspectives that motivates their actions and their discourse. Discernment becomes important when it comes time to identify the nature of that agenda. What is driving the actions of the people we interact with and listen to? What is driving our own actions? As believers, this is a particularly important line of questioning to explore when trying to decide what influences to follow and what instruction truly represents the voice of Christ.

In commenting on the tenth chapter of John, early church father John Chrysostom highlights the differences in agenda between that of Jesus and that of the political rebels with whom He would later be compared (see Acts 5:27-40).
"They did all as rebels, and to cause revolts, but He placed Himself so far from such suspicion, that when they would have made Him a king, He fled...Besides this, He indeed came for the saving of the sheep, That they might have life, and that they might have more abundantly (John 10:10), but the others deprived them even of this present life." (The Homilies of St. John Chrysostom on the Gospel of St. John)
The rebels had an earthly agenda. They may have had a justifiable agenda, but it was still earthly. They sought position, authority, and political influence.  Furthermore, the scope of their agenda encompassed only the narrow interest group to which they belonged. But Christ's agenda was always focused on the Kingdom of God and not on earthly power. 

And what was the scope of His agenda?

It was quite broad. He served and gave of His time to children, sinners, lepers, women, and those who did not share his religious tradition. He even gave His time to those who had distorted His religious tradition.

To follow the voice of the Shepherd is to emulate this mysterious and beautiful example. It is to travel beyond the confines that our earthly and narrow self-interest would set. To follow the voice of the Shepherd is to walk among the strangers: the people society would ignore, the weak, the vulnerable, the needy, the sick, the imprisoned, the lonely, and even the ones with whom we do not agree. The voice that calls us to exclude, ignore, or turn away from those that do not share our narrow band of experience and limited perspective--this is the voice of the stranger. It is a voice motivated by fear and insecurity.

To heed the voice of the Shepherd is to follow Him outside our comfortable boundaries, outside the divisions that society and convention have arbitrarily imposed on us. We are not a demographic group, we are the Church: the living, moving, energetic bride of Christ. And we must be prepared to follow Him into places we would not expect to go, so that we can serve, love, and engage with others--whoever and wherever they may be. That is our agenda.

Reference: SCHAFF, DR PHILIP. "Volume XIV." SELECT LIBRARY OF THE NICENE AND POST-NICENE FATHERS,: The Christian Church. S.l.: FORGOTTEN, 2015. N. pag. Print.