The most comforting of the Psalms begins with the line: “The Lord is my shepherd.” It ends with this line: “Goodness and mercy shall follow me all the days of my life.”
Goodness and mercy, in the person of the good Shepherd, have to follow, because the shepherd is heading out to seek the lost sheep. The sheep is leading the way, and that is why the sheep is lost. The shepherd is the one who knows the way and ought to be leading, but he has to follow because the sheep got out ahead of the shepherd and so got astray.
In the Gospel Reading, Jesus says that his sheep follow him. Those who belong to him know his voice and so they are willing to follow him and let him lead the way.
Now the Shepherd is a person. And knowing a person is a matter of personal relationship, with all the risks and vulnerabilities that personal relationship entails.
So a faithful sheep is in a personal relationship with its Shepherd and loves him. That is why that sheep knows the voice of the Shepherd and follows him.
Here is the good news, then. Whether a person is faithful or lost, he will be surrounded by the love of the good Shepherd. Either the Shepherd will lead him, or the Shepherd will follow after him to find him when he is astray.
And so St. Patrick’s prayer is right: Christ before me, Christ behind me. And, either way, Christ with me.