I have no supportive data for this reasoning, but I believe one specific reason teenagers leave the church is that they lack an understanding on two things: 1) what the Church is, and 2) how to be a faithful local church member. And the way we see it is simply through the rise of our youth leaving our churches after high school graduation. Here’s what a 2007 research study from LifeWay presented:
“Six of the top 10 reasons church dropouts leave relate to life changes. The most frequent reason for leaving church is, in fact, a self-imposed change, “I simply wanted a break from church” (27 percent).
The paths toward college and the workforce are also strong reasons for young people to leave church: “I moved to college and stopped attending church” (25 percent) and “work responsibilities prevented me from attending” (23 percent).
In addition to moving to college, others simply “moved too far away from the church to continue attending” (22 percent) and, it can be assumed, did not find a closer church.” 
It may not seem as if my argument and the LifeWay research coincide with one another, but I believe with further analysis they will. However, to analyze correctly and to find a solution, we need to define what it means to be the Church both visibly and invisibly, and what it means to be a faithful church member.
The Visible and Invisible Church and Its Members
Being a part of the invisible Church essentially means you are a child of God by adoption through faith and belief in Christ’s sacrificial, substitutionary death on the cross in your place (Gal. 3). In the Old Testament, this covenant (invisible) people was the Israelite nation. This was God’s way of distinguishing/separating a people for Himself. We can even see in the New Testament (Hebrews 11:31; Romans 10:8) that some were grafted in because of their obedient hearts toward God’s people.
Further, in the New Testament, it is abundantly clear that we are adopted into God’s family via regeneration (John 3:5; Ephesians 1:5; Galatians 4:5-6). This regeneration is immediately connected with and followed by the adoptions as an heir of God’s family. As related to the people of Israel, Paul wrote to the church at Rome that not all of Israel’s descendants are the bloodline of Israel himself (Rom. 9:6). Without going into too much theological debate, Romans 9:6 gives us assurance that those adopted into God’s family are not only from Israel’s bloodline descent but also for those who place their faith in Christ’s atoning work on the cross for their sins.
This aspect shows us that being a part of the invisible church means to be a part of God’s family as an adopted son or daughter. You are a child of God because you have placed your faith in Christ’s sacrifice for your sins and have allowed him to be Lord of your life. As pastors to students, it is imperative to remind them that they have a place in God’s family as much as anyone else!
Yet, being a part of the visible church has a couple more implications. (As a much broader topic of membership and its importance, I’ve written about it here.) By becoming a member of Christ’s Church through a confession of faith in Christ Jesus and through believer’s baptism, you then become a part of the visible church. But what is church membership? How do we categorize ourselves as “members” of a local body of believers? Mark Dever posits this idea,
“Careful practices of membership and discipline are meant to mark off the church from the world and thereby define and display the gospel.” 
Dever is spot on in his examination of church membership. Membership is what marks off Christians from the world. Church membership essentially says “we will do all things necessary to represent the gospel of Jesus Christ AND OUR LOCAL CHURCH well.” Of course, this brings up more questions about teaching and discipling students on several things: 1) what the church is; 2) how the church operates; 3) what a church member is; 4) what it means to act out your life in obedience as a church member.
Church membership, I believe, it vitally important for student ministry. In my experience, I have noticed that students feel as if they do not belong to their respective churches. I’ve had students tell me to my face that this is the case. My sneaking suspicion is that the students I pastor are not the only ones who feel this way. And while feelings are not always helpful to describe reality, it does give us some insight into what it means to be a teenager in the local church.
Theology and Student Ministry
In his book, Taking Theology to Youth Ministry, Andrew Root writes:
“The very fact that youth ministry is ministry means that it is theological – for it seeks to walk with young people as they encounter the God of the burning bush.”
The very nature of all ministry is theological. You can never truly shy away from theology if you are in any sort of vocational ministry. It’s the lifeblood of the church. Theology is what drives our methods. It’s the standard by which we operate our churches in all areas of our polity. For this reason, I believe it is also necessary to meld theology into our student ministry, or vice versa.
The reason theology must be melded together with ministry methodology is that the two are inseparable. There is no such thing as ministry without theology. There is no such thing as having a correct theology that does not ignite within you a desire to carry it out practically in everyday life. Here are a few reasons for the necessity of theology in student ministry:
- Theology, through the lens of His revealed Word, is the means by which we know God. As LifeWay’s research proved, young people are leaving the church because they “wanted a break from church.” The reason for this leaving, in my opinion, is because we’ve neglected to influence teenagers to get into their Bibles. The Christian life is impossible apart from Christ’s power and the Scriptures. We cannot know Christ without the Scriptures. Therefore, we must influence those under our leadership to find joy in knowing Christ more than anything else in life.
- Students need a foundation on which to build a worldview. Jesus spoke of a wise man who built his house upon the rock in Matthew 7 and there are multiple implications within this passage of Scripture we could use in context. However, I believe there is an implicit principle involving every believer to build their spiritual house on a firm foundation. It’s Christ that is the cornerstone of our bodily temples (Eph. 2:20) and it is Christ who is the foundation of the Church (Matt. 16:18). Therefore, we must influence students to get into the Word until the Word gets into them so much so that their foundation has no other blueprint but Christ himself.
- We learn the things of God by the means of theological study. I want to be clear that nothing takes the place of Scripture. That Scripture is the inerrant, infallible Word of God is not a back-burner element of Christian theology. The Scripture is what drives us to the study of theology. God’s revealed Word is the means by which we know and understand God and His character. Our number one priority is to know Him through His Word. But His Word should ignite a desire in believers to dive deeper into the depths of theology to know Him more.
- Students need theology today more than ever. It is no secret that our world is post-Christian. Anyone living in the American cultural landscape can see our world is most definitely not influenced by Christianity as it once was. Because of Christianity’s fading away, it is imperative to help our students understand the nature of apologetics and what it means to be a Christian. Theology (alongside apologetics) aides you in doing just this. Students need a very firm foundation to simply defend the Christian faith in our world.
- Theology informs the way you disciple students. Students need mentors who are willing to help them navigate through the tough questions they face every single day in our post-Christian landscape. This type of mentoring and/or discipling stems from the older generations of our churches modeling and influencing this type of godliness. Kenda Creasy Dean writes:
“So we must assume that the solution lies…in modeling the kind of mature, passionate faith we say we want young people to have.” 
Although theology can be very academic, it can also be very practical. The best way to meld theology into your ministry is to teach it clearly and explain why it is necessary for the everyday life of the church.
Students need a firm foundation on which to build their worldview. It is our job to show them just how firm a foundation that has been laid for our faith.
 “Reasons 18- to 22-year-olds Drop Out of Church,” LifeWay Research, August 7, 2007, accessed July 28, 2018, https://lifewayresearch.com/2007/08/07/reasons-18-to-22-year-olds-drop-out-of-church/.
 Mark Dever. The Church: The Gospel Made Visible (Nashville: B&H Publishing, 2012), xxiii.
 Andrew Root. Taking Theology to Youth Ministry (Grand Rapids: Zondervan, 2012), 56.
 Kenda Creasy Dean. Almost Christian: What the Faith of Our Teenagers is Telling the American Church (New York: Oxford, 2010), 4.