It’s all about worship
The last and most particularly dangerous expression of naivete that comes to mind is the "it's all about worship" expression. And by worship, these young Christians have in mind song and corporate music and all the accouterments thereof.
The problem with this expression is not the focus on worship - for worship is of primacy in the believer’s life. The problem is the distortion of what it means to worship God. Scripture teaches us that worship begins with and ends with obedience. We worship God when we obey him first. the OT teaches us so often that great emotional worship services are worthless, even vile in the mind and face of God, if there is no obedience. God despises worship services from those who do not obey His word.
One way to think about worship is to see it as the ascription of worth to another. We cannot make God out to be worthy in our lives and minds and hearts if we despise his commands. The mature begin with the commandment. the young and naive begin with the emotional expression. Again, it's not that they're evil or bad Christians (if in fact, they are Christians - something we should never take for granted); they're just immature and inexperienced and their emotions are going to be so useful one day, when obedience guides them.
A good analogy is young love. We all remember that teenagers fall more deeply "in love" than anyone - e.g. Romeo and Juliet. But without maturity, that powerful emotion leads to not to true love, but death as Shakespeare demonstrates poetically if not figuratively. The mature love is one that is guided by principal first and allows the emotion to express it, not define it. It is universal to see youth get particularly emotional in worship service only to sink into sexual sin and worldliness the next day and I wonder, when and how will they learn to seek Godliness first? I see young men confuse lust for love and clamor for an ungodly woman they're not suited for simply because their hormones are confused and excited. I see young women confuse emotional immaturity and neediness for love and desire ungodly men. These children in the faith have not thought it through, prayed it through or obeyed it through. They're not seeking Godly advice or parental guidance. They're being carried away, as Scripture says, with every enticing doctrine and style of expression. And they feel OK about it because they can have a powerful worship experience on Saturday night or on Sunday at the contemporary service.
But emotional entanglements with the opposite (or indeed, in today’s church - same) sex is only one sin that so easily entangles our young in the Faith. The principal sin I see ubiquitously tolerated and embraced by Christians everywhere is the sin of worldliness - that sin of taking what the world gives and embracing it into our hearts and minds. Television, romance novels, morbid fascination with blood sucking vampires and morphing beasts and teens, movies about torture, movies about adultery, movies about deception, immodest dress, uncouth speech, lack of respect for elders, disregard for serious study of Scripture - all of these things more mark the average youth group in today’s churches than do the fruits of the Spirit. And sadly, these are the marks of so many older Christians who have no excuse for their immaturity.
Sinful disobedience prevents true worship. If you have sin in your heart that you have not fully repented of - turned away from - hated in your heart - confessed to your sisters and brothers - abhorred in your spirit, devised plans to prevent yourself from falling back into - if this sin still infects your heart - God does not hear your singing praise songs... He does not delight in your waving of flags or spilling of tears; God is not amenable to your ministry work, your evangelism, your short term ministry trips abroad, your digging of wells, or your feeding of the hungry. God despises and desires obedience. Get over yourself and stop sinning.
The Gospel is simple in that you sin, God hates sin, God provides a sacrifice for sin, God wants you to stop sinning. The Gospel is divinely complicated and mysterious insofar as it involves God Himself acting of His own accord, accomplishing all that is Salvation - giving us faith - giving us the Spirit and providing a means out of sin. It is simple from ten thousand miles away, but the closer you get to God, the bigger He is - the more majestic He is, the more mysterious He is, the more Glory He has, the more Godlike He becomes. If your god is simple - you’re still too far from God - stop sinning and go to God. Therein are the deep waters. Therein are the mysteries.