The clock is ticking. If you're faithfully "preaching the gospel" to your own soul, day in and day out, but distancing yourself from regular Bible intake, your freshness is fading. There's an expiration date on this fruit once it's off the vine.
Don't think I'm down on preaching the gospel to ourselves. I love it. I commend it. It's one of my main conscious sources for sanctification, an indispensable weapon for fighting the fight of faith. I'm eating this fruit daily. Warning you about the "shelf life" on gospel self-preaching is in hope of guarding and preserving this precious reality in the Christian life.
Gospel and Scripture — Together
The concern is that those of us convinced of our ongoing need for the gospel should take care that our so-called gospel centeredness not lead to laxity with the Scriptures. God has designed the two to be united. And what God has joined together, let no man separate.
Without relentless reorienting on the gospel, our study of the Scriptures quickly veers off course. And without keeping ourselves freshly filled with the Scriptures, our gospel self-preaching soon runs on empty.
Gospel Perspective in Scripture Reading
John 5 shows the folly of fixing on the Scriptures while ignoring the God of grace. Jesus crossed paths with a troop who liked to think of themselves as soaked in the Scriptures, but they were getting them all wrong, taking them in through the wrong grid. What an epic tragedy: They had God himself in the flesh, standing in their very midst, and they missed him because their Bible reading was going awry with self at the center.
Jesus says to them, "You search the Scriptures because you think that in them you have eternal life; and it is they that bear witness about me, yet you refuse to come to me that you may have life" (John 5:39–40). The lesson for us is to never disconnect our searching of the Scriptures from a conscious awareness and pursuit of Jesus as our Savior, Lord, and Treasure. The gospel of Jesus is the core, culmination, and meaning of the Scriptures. No matter how passionate the study, regular Bible intake that is not in accord with the truth of the gospel becomes zeal without knowledge.
Displace the gospel from the center, and studiousness with the Scriptures soon becomes a massive self-salvation project.
Bible Intake and Preaching to Yourself
But there's another side to the coin, and it's the one that's our focus here. God does not intend for the message of the gospel to get cut loose from the Scriptures either. Regular Bible intake — whether it's reviewing memorized Scripture, Bible-infused conversations with fellow believers, or receiving the public preaching of God's Word — serves to shape and strengthen and sustain the daily preaching of the gospel to ourselves. The Scriptures, rightly understood with Jesus at the center, nourish our hearts, and sharpen our minds, to be able to rehearse the truth of the gospel with texture and edge and definition, with freshness and power.
The message of the gospel is not meant to be something we "get," carve into canned lines, and tell ourselves over and over for a lifetime as some sort of magic to fight sin. God means for us to be regularly pushed and formed, hurt and healed, challenged and encouraged by passages we've never heard before, haven't given enough attention to, or haven't considered in a while. He means for us to understand even our best known verses at new depth, and know the power of his grace more deeply, through new applications, as we encounter situations in life we've never faced before.
Keeping Your Gospel Fresh
This is why he gives us teachers, fellow believers, and access to his objective, "external word," as Luther called it, amazingly preserved in a Book for millennia, to continue shaping and upholding the church today. He means for us regularly to hear other Christians articulate the truths most precious, and to be pressed time and again with God's own inerrant speaking in human language in the biblical canon.
So, yes, keep the gospel central in sanctification. Eat daily from the fruit of preaching the gospel to yourself. And keep your stock fresh with regular picking from the cornucopia of Bible intake in its varied forms.