Why is superficiality so enticing as an answer to diversity of thought and pluralism?
I think it's enticing because it allows us an easy retirement from the fight. Diversity of thought breeds conflict, so it's simply easy to become so superficial in our relationships by snipping away at who we are and what we really think until we find common ground, which is usually going to be on something not worth discussing, as it has no real effectual influence on our lives. Hence, our interactions with other people either become flattery sessions, where we merely just encourage others in what they're doing regardless of what we think about it, or they turn into unity around some menial experience or idea. The quest to find common ground is often a quest to kill off the profound and important in our relationships. Even evangelicals argue that we should major on the majors in order to get along, rather than teach and discuss the whole counsel of God, but even the majors are becoming the source of too much conflict. At the end of the day we end up with just agreeing to allow Christians to believe in God in some way, in Jesus in some way, and let everything else drift to the wayside in our conversations with one another.
And why do we do this? Because we get tired of conflict. Diversity of thought creates opportunities for conflict if, in fact, one or more people are willing to stand up for what they believe in. And we don't like conflict. It takes energy out of us. It takes work to overcome. And we are exhausted by it. Hence, the easy answer is just not to engage anymore in such conflicts. Make your interactions all happy ones.
The other answer is to simply surround yourself with people who agree with everything you say, or at least, agree that what you believe is valid in some way. Hence, no real criticism of what you believe or do is available to you. In other words, there is no ability for what you believe or do to actually go through a process of purgation of anything that might be harmful or fatal to your life.
The problem with avoiding conflict by retreating from critical conversations that are brought on by conflicting thoughts is that we become only shadows of what we were meant to be. We become superficial humans ourselves, never allowing our ideas and practices to be evaluated for their truthfulness or goodness. In short, we become empty people who can't take criticism, since our ideas have not been tried and tested by friends. All who would do so look like enemies to us. All who would engage in deeper conversations and stand up for what they believe as the true and the good in exclusion to bad ideas are to be avoided. Conflict goes away. The world's concept of peace ensues. And we are left as happy, shiny people holding hands. There's just not much left of the "people" part, or the "happiness" part, since we are made for deeper relationships than that. Perhaps, it would be better to call us "accommodating, dull subhumans waving at each other." That about sums up the amount of true depth we're getting with one another, along with the amount of genuine satisfaction in becoming all that we were meant to become in our relationships with one another as humans.
In fact, it becomes impossible to have any idea that what you believe is true, since others are often given to us to question what we believe so that we might sharpen one another. True knowledge, then, becomes impossible, or at least, improbable, to actually discover, beyond just being plain lucky or blessed to have stumbled upon such a perfectly cut diamond right out of the coal mine. We need each other to learn, but learning beyond what you already believe is impossible to do in superficial or self-flattering relationships.
For Christians, however, superficiality is not an option. We are commanded to go into all nations and teach them all that Christ has commanded, not just the stuff that everyone would commonly see as true and good. We are commanded to engage in a spiritual warfare that is not against flesh and blood, and to hold every thought captive to Christ. Our goal is not to get along. It is to transform subhumans into real humans in Christ, and we do this by entering real relationships that are brought on by real conversations that often have a lot of real conflict. The Christian may not get to hold hands with those who reject the truth he brings, but as said before, they're not really holding hands with each other either.
Instead, our goal is to not become exhausted by conflict, but to see it as opportunity for transformation and growth toward what is true and good and bring others under the loving Lordship of the Lord Jesus Christ. This is why we are continually exhorted to not grow weary in our struggle against what is wrong by doing what is good. We are to speak the truth to everyone, and have the love for others as our motivation for doing so. We are to fight the good fight, to keep the faith, to exalt Christ in every conversation possible. Search the Scriptures and you won't find a single superficial conversation that God has with His people. You won't find Christ just talking about sports or the weather. Even the mundane is turned into something profound by Christ, because He is infinitely profound. But His depth and stand for what is true created nothing but conflict in the world of the superficial and the evil tendencies of man who desires peace at the cost of what is right. I wish the same could be said of all of His children.
And He gave some [as] apostles, and some [as] prophets, and some [as] evangelists, and some [as] pastors and teachers, for the equipping of the saints for the work of service, to the building up of the body of Christ; until we all attain to the unity of the faith, and of the knowledge of the Son of God, to a mature man, to the measure of the stature which belongs to the fullness of Christ. As a result, we are no longer to be children, tossed here and there by waves and carried about by every wind of doctrine, by the trickery of men, by craftiness in deceitful scheming; but speaking the truth in love, we are to grow up in all [aspects] into Him who is the head, [even] Christ . . . (Eph 4:11-15)
And this I pray, that your love may abound still more and more in real knowledge and all discernment, so that you may approve the things that are excellent, in order to be sincere and blameless until the day of Christ (Phil 1:9-10)
Do not withhold the truth from one another, since you laid aside the old self with its [evil] practices, and have put on the new self who is being renewed to a true knowledge according to the image of the One who created him-- (Col 3:9-10)
Beloved, while I was making every effort to write you about our common salvation, I felt the necessity to write to you appealing that you contend earnestly for the faith which was once for all handed down to the saints. For certain persons have crept in unnoticed, those who were long beforehand marked out for this condemnation, ungodly persons who turn the grace of our God into licentiousness and deny our only Master and Lord, Jesus Christ. (Jude 3-4)