"About this we have much to say, and it is hard to explain, since you have become dull of hearing. For though by this time you ought to be teachers, you need someone to teach you again the basic principles of the oracles of God. You need milk, not solid food, for everyone who lives on milk is unskilled in the word of righteousness, since he is a child. But solid food is for the mature, for those who have thier powers of discernment trained by constant practice to distinguish good from evil," (ESV).
Those are blunt words. The author of Hebrews was rightly frustrated with the recipients' apathy (v. 11). They had not trained thier powers of discernment by constant practice (v. 14). Though by that time they should have been able to understand theological "meat", they were still in need of "milk" and coddling. This was not the sort of child-like faith that Jesus affirmed (i.e. Matt. 18:3-4). This was the perpetual, intellectual immaturity of undisciplined believers.
Nearly 2000 years later, we're inflicting ourselves with this same condition.
Orthodoxy theology is not simple. Even Peter pointed out that, "There are some things [in Paul's letters] that are hard to understand, which the ignorant and unstable twist to their own destruction, as they do the other scriptures," (2 Pet. 3:16, ESV). Apparently he'd read Romans. And yet, despite this difficulty, in Romans Paul tells us to "be transformed by the renewal of your mind," (Rom. 12:2b). Understanding and engaging worldviews is not simple. And yet Paul was careful to understand the world in which he lived so as to engage the thinkers of his day and relevantly proclaim the gospel (Acts 17:16-34). Answering the tough questions and objections of our non-believing collegues, family, and friends is not simple. And yet Peter tells us to, "always [be] prepared to make a defense to anyone who asks you for a reason for the hope that is in you," (1 Pet. 3:15, ESV). The sort of disciplined intellectual training required to increase our theological understanding, engage our world, and answer tough questions is the sort of "meat" we need as a part of a healthy spiritual diet. I'm afraid we're just too comfortable wrapped up in blanket with a warm bottle of milk. And that's not without consequence.
First, from my vantage point, it does seem that as science and philosophy have progressed, theism in general and Christianity in particular have declined. I'm not claiming to have any sort of new, in-depth study to support that observation. I'm sure you'd be able to find some sort of stastical data to the contrary just as I'd be able to dig up some support. For now, if nothing but for the sake of argument, consider that the progression of science and philosophy along with thier popularization have had at least some negative impact on American, Christian faith. That should not be!
Some (perhaps even many) have suggested that this trend "proves" that Christian faith isn't rational. Christianity is a supersticious crutch for the ignorant. As physics and meta-physics have definitively rendered faith in Zeus irrational and unnecessary, so to will faith in the divinity of Jesus Christ soon be obsolete. But this isn't a problem with the reasonability of faith itself. What we're witnessing is the decline of unreasonable faith. Christians, at least at a congeragtional level it seems, have lost interest in physics. It's too hard and it's worthless anyway. Physics is just a worldly tool the devil uses to convince people there is no God. But when faced with some good physics in a high school classroom (or even some of the watered-down physics on the Discovery Channel), this sort of unreasonable faith is subject to crumble.
The tragedy is that these Christians have missed out on the opportunity to see that even the conclusions of a lot of really good, atheist physicists actually support theism and Christianity! And the same goes for philosophy.
All this affects our ability to be faithful witnesses and heradls of the gospel. Indeed the Holy Spirit plays a vital and definitive role in evangelism; it's crutial that we recognize that. But the Spirit's work is not an excuse for us to be lazy. If we hope to contend for the plausibility of Christianity, if we hope to demonstrate to this world that the Bible really is true, if we want to take advantage of the opportuntiy that T.V. shows like Cosmos create for evangelism, then we need to move on from milk to solid food.
Second, if we live as theologically immature people, we limit our ability to live abundantly. I don't maintain any illusions that there will be thousands of people reading my blog; I'm glad to have the handful of you who have made it this far. But I can't help thinking that a subset of that handful has moved on to other things before they made it as far as this sentence. They were hoping for something a bit more... warm and milky. They wanted to be blessed by positive and encouraging words, not waste time reading about the importance of physics. For too many Christians anything that requires much thinking isn't really worth thinking about.
The tragedy here is that Christians miss out on the abundance of life there is to be found in knowing difficult truths. Yes, words and concepts like propitiation, sanctification, and grammatical-historical exegesis may take a bit of effort to grasp, but they are deep wells of edifying truth. A good portion of orthodoxy is both intellectually challenging and devotionally edifying. The better we understand God and his perspective, the more we will live abundantly. Thus Jesus said, "If you abide in my word, you are truly my disciples, and you will know the truth, and the truth will set you free," (John 8:31b-32) not to mention, once again, Paul's command to, "be transformed by the renewal of your mind," (Rom. 12:2b). That the recipients were missing out on the abundance that comes from a diet of "meat" was, I believe, what caused the author of Hebrews to be so frustrated with thier settling for milk.
Far be it from me to reduce Christianity to theological data-gathering. Nor do I want to suggest that all mature Christians need to be PhD astrophysicists and systematic theologians. A Christian community of believers able to explain penal-substitutionary atonement and well versed in the Kalaam cosmological argument is only good to the extent that those same believers are in deep, active, and personal relationships with Jesus Christ. But by this time, standing on the shoulders of 2000 years' worth of giants, we Christians ought to train with constant practice our powers of discernment and eat a steady diet of solid theological food. On this side of eternity, though we may grow to be teachers, we will never become masters; our pursuit of a better understanding of the truth will never be complete. But it's time we give up our blankies and bottles and get serious about growing up.
Grace be with you.