I’ve often heard people say that spiritual maturity has nothing (or very little) to do with growing intellectually in the faith. That somehow, true spiritual growth is defined by what you do and not how much you learn.

I have no idea what that means. Growth in Christ comes by the renewing of your mind (Romans 12:2). And that entails learning spiritual things.

Once we learn new things, we can put them into practice. Correct theology begets correct living.

The idea that a Christian can grow and live spiritually without loading up on Biblical truth is a strange one. But it’s a popular view often presented as a humble way to approach the Christian life. After all, doesn’t knowledge “puff up”? Isn’t living like Christ more important than mastering sound theology?

Not really. The Bible puts equal emphasis on both practical Christianity like praying, loving, and serving (1 Thessalonians 5:17; Galatians 5:14; 1 Peter 4:10) and loving the truth, which involves holding to it, preaching it, and guarding it (Titus 1:9, 2:1; Jude 3). You can’t have one without the other.

But these days many Christians can’t be bothered with the workings of sound doctrine. I suppose a dark history of burning each other at the stake over theology put a damper on the call for learning systemized truth.”Doctrine divides; love unites!” is as prevalent a cry as it ever has been.

Yet consider what the author of Hebrews had to say:

“…though by this time you ought to be teachers, you need someone to teach you the elementary truths of God’s word all over again. You need milk, not solid food! Anyone who lives on milk, being still an infant, is not acquainted with the teaching about righteousness. But solid food is for the mature, who by constant use have trained themselves to distinguish good from evil. (5:12-14)

Apparently, he was expecting his audience to have matured enough in their faith to be teachers of spiritual truth.  Instead he finds them still as spiritual babes, unable to discern good from evil, let alone teach the faith. They needed “the elementary truths of God’s word all over again” – the equivalent to baby milk, which is all their undeveloped minds could take.

Why is it so important to move onto “solid food”?

I can think of three reasons.

A Strong Foundation

“Therefore everyone who hears these words of mine and puts them into practice is like a wise man who built his house on the rock. The rain came down, the streams rose, and the winds blew and beat against that house; yet it did not fall, because it had its foundation on the rock.” (Matthew 7:24-25)

When you make Jesus’ teaching the bedrock of your faith, you’re invincible. Notice how Jesus says, “everyone who hears these words of mine and puts them into practice” won’t be shaken? It’s about understanding (hearing) and doing (practice). You can’t practice what you don’t understand.

It’s also important to actually live out the things you believe in, to let your knowledge of the truth shape your behavior. Knowledge that isn’t acted upon leads to destruction; it’s like building a house on the sand (v 6). When the storms of life and the attacks on your faith begin to pummel you like a relentless tsunami, you can bet your house will be swept away in the chaos.

If we’re grounded and growing in the truth and power of Scripture, we can rise above any situation and help others do so too. Which leads us to:

Effective Outreach

We are all called to proclaim the gospel and the beauty of Christ (Matthew 28:19-20). But how can we do so if our knowledge of the Lord is thin? How can we win others to Jesus if we ourselves have little comprehension of man’s depravity, the nature of salvation, and God’s sovereignty over the entire process?

How can we mutually build each other up if we can never progress from the elementary truths of Scripture? How can our messages of hope to one another be anything more than fluff if we’ve never feasted on the meatier aspects of our faith?

It’s hard to win people to Christ; it’s even harder to raise a flock of healthy believers. The work is all the more cofounded by people who harbor weak doctrine and an unwillingness to learn the deep truths of God.

We need to continuously steep ourselves in the Word and fortify our doctrinal foundations in order to make more effective presentations of Christ and His truth (2 Timothy 3:16-17).

Defending the Truth

The Bible makes it clear we are to be ready with an answer for people who might ask why we believe what we believe (1 Peter 3:15). We must also be ready to teach the truth and refute those who stand in error (Titus 1:9).

Failure to defend the faith will allow others to steamroll over the truth with their heresies. This can be disastrous for people who have yet to hear and respond to the gospel.

A case in point? Roman Catholicism. If we can’t even present a correct gospel to people trapped inside this insidious and apostate system, if we can’t refute the numerous heresies perpetuated by the Roman church, then how can we expect Catholics to come to a true saving knowledge of Jesus?

We must be able to take a stand and effectively defend the truth when called for.

Now does this mean we should all enroll in Bible school and become masters of theological wizardry? Do we need to commit to unfailing memory every jot and tittle of Calvin’s Institutes or Wayne Grudem’s Systematic Theology?

While that might be very cool, not everyone has the mental capacity to be an RC Sproul or Augustine. But that doesn’t mean we should shy away from the deeper mysteries of the Bible. Rather, we must be compelled to learn continuously about Christ, to embrace His revealed truth, to cherish it, uphold it, and let it transform our minds and daily living.

We fail to do so at our own peril (Hosea 4:6).