Speaking of his students, Aristotle said there are basically two times to get a boy’s attention. The first is between the ages of one to five and the second between the ages of fifteen to twenty. After that he is a lost cause, said Aristotle.
Those are two very formative periods. The period from one to five is when a child learns his or her place in the world—his or her identity—and leaves with a world picture. But when a child leaves high school, he or she has a worldview. Those are two different things.
The difference is the complex analytical capacity that comes in adolescence: the ability to understand one mind among other minds. It’s the ability to understand that what this child has received from mom and dad is not exactly what everyone else receives from their mom and dad. What they receive from the preacher is not what others are hearing. There are alternative worldviews.
I would simply say that there is an offensive and a defensive play here. Both of them are very important.
Offensively, we need to help students when they are thirteen to understand how to judge other truth claims and worldviews—because they are going to be inundated with them—by the unchanging authority of God’s Word. Build in them, insofar as you are able, an instinct to turn to the Word of God and to trust the Word of God. There is no way you can comprehensively prepare them for all the intellectual challenges they are going to face, but you can at least model for them what it means to trust in Scripture and to know that there is a way of understanding all truth that is accountable to God.
And defensively, this is very important: it’s not just their minds, it’s their hearts. It’s important to talk to a thirteen-year-old and let them know that a battle for their minds is ensuing but also a battle for their hearts. The defensive play is not only to pray for them and to teach them, but also to help them understand your joy in Christ. Because there are all kinds of competing affections that are going to be presented to them very quickly. Let your affection for Christ be something that they remember.