The Scientific Challenge
Throughout the school-age years, our children are constantly bombarded with the idea that science is superior to any religious belief in its grip on reality. They are taught that naturalistic Evolution is the only possible conclusion from the data, and it is proclaimed to be science fact. Of course, we know this to be untrue, but we must equip our children with sound reasons to believe that we are telling them the truth. They are given evidence by the academy for its positions; therefore, we must do the same. When we give our children sound counter-arguments to weigh against the arguments of the opposition, they are less likely to blindly accept the opposition. That will place them on firmer ground and prepare them as ambassadors for the Gospel of Jesus Christ to a polarized(ing) world so deeply in need.
The Philosophical Challenge
Of course, the scientific debate is not the only challenge that our children will face. They will be confronted by other world religions, the cults, and other philosophies. In the humanities at university, they will be guided to believe that there are no absolutes (truth or moral). It is our job, not only to provide our children with a scientifically and logically sound arguments for their beliefs (1 Peter 3:15), but to see that they understand correct Christian doctrine (i.e. about God, Christ, the Trinity, sin, etc...). No one will be forced into the Kingdom by an impenetrable logical argument. In some cases man's pride will cause him to make the most ridiculous and fallacy-ridden arguments before he accepts his need for a Savior. I am convinced that the further man moves away from God, the more illogical he becomes. I also believe that the more illogical man becomes, the further he moves away from God.
Faith is Logical and Emotional
Having said that, we also need to cultivate a love for Christ in our children that burns until they are consumed with it. Christ told us "If you love me, you will obey what I command." (John 14:15) This was not a statement of how to prove to Christ that you "love" him (works-based theology, but that's a different topic), it was a statement of how the world will be able to identify Christ's love in you (see also John 15) and see that you are acting on what Christ taught (in an effort to avoid hypocrisy). Christ summed up all His commands with this simple phrase, "Love the LORD your God with all your heart, soul, mind and strength and love your neighbor as yourself" (Luke 10:27, Italics mine). Providing an apologetic argument to others is part of loving God with our mind and loving our neighbor enough to help him overcome his doubt, so that he can enjoy the gift that Christ has given to us of the freedom from the separation from God.
Unfortunately, I have seen too many youths who considered themselves Christians, then lost their faith when they got into the world. Most of them state that a college professor was able to reason them away from a belief in God altogether. Or a coworker with a different worldview quickly convinced them that there are many ways to God. I have also asked kids (before they get to this point) why they believe in Jesus Christ. Many of them simply say "because the Bible says so". If I was an unbeliever, why would I accept that as a valid reason if I didn't accept the Bible as a valid source of truth in the first place?
To Youth Leaders
I have seen in many of our churches that the youth group is spending too much time trying to "babysit" youth rather than teach them to understand the reasons and foundations for their faith or equipping them with sound tactics for evangelizing to the skeptics. I'm not saying that we aren't teaching our children about Jesus and all the stories in the Bible. What I am saying is that we spend too much time stressing memorization, and not enough time understanding how and why our Faith is coherent, logical, and most importantly, TRUE.
I also don't see (anywhere) where our youth are taught to appeal to extra-Biblical sources in their witness. Unbelievers don't accept the Bible as a source of truth (I found that out the hard way in my early college years); so the witnessing Christian who only uses the Bible is at a great disadvantage and limits the work of the Holy Spirit. Yes, the Holy Spirit pushes people toward the Gospel, but it is ultimately the person's choice whether to accept it or not. Yes, the Holy Spirit works through the believer to witness to that person. But, our knowledge and understanding limits what we can do. God works through Christians, but we place limits on how God can use us by limiting our knowledge and understanding. God gave us a mind. He commands us to use it. He also commanded us to make disciples of all people. Therefore, we should use our mind to make disciples of all people.
Our youth have the opportunity to be the most powerful ambassadors for Christ in the academy. If they can soundly challenge the crap that is being force-fed to them, they not only strengthen themselves, they strengthen other (less knowledgeable) believers, and they sow many seeds of doubt about the alternatives in the minds of unbelieving students. Imagine how the Holy Spirit could use our youth who choose not to place intellectual limits on themselves.
Christianity is different from every other religion, not just because it is the truth, but it can provide the Believer with spiritual, emotional, and intellectual fulfillment. If we allow God to work through us to show our children how fulfilling knowing the One True God can be, there is no end to how God can and will use them to reach this dying world.
Jesus made the most radical claim in history: "I am the Way, the Truth, and the Life; no man comes to the Father except through me." It is time we teach our children how to defend that statement.