One of my favorite books is D.A. Carson’s How Long, O Lord? No other book has shaped my view of suffering like Carson’s. It was not written for the suffering believer, however. Carson writes in the preface, “[T]his is a book of preventative medicine…we [dangerously] do not give the subject of evil and suffering the thought it deserves until we ourselves are confronted with tragedy.” How Long, O Lord? Is not so much a book designed to lift the believer out of debilitating suffering as it is one designed to give the joyful believer a framework for when suffering comes. In other words, the book was helpful because I read it before I needed it, not when I needed it.
Think of a virus. Treatment in the midst of a virus is helpful and lifesaving. However, a vaccine for a virus is far better because it keeps you from getting the virus in the first place. Our theology should operate the same way. Theology is helpful as a response to suffering and struggle. It is a legitimate treatment in these times. But theology also operates as preventative medicine. As a vaccine helps to prevent unnecessary sickness, so theology helps to prevent unnecessary suffering and struggle.
Christians must think on the things of God before they need them. If you wait to learn to fight temptation until sin ambushes you, you’ve waited too long. You won’t be able to resist one temptation, let alone a sustained season of it. If you wait to learn to suffer well until suffering overcomes you, you’ve waited too long. You’ll experience more anguish than you would if you had considered the goodness and sovereignty of God beforehand.
We must teach theology in our churches before it is needed, not after. Teaching the providence, goodness, and sovereignty of God before suffering makes the suffering bearable when it comes. Teaching the holiness of God and His hatred of sin prepares believers to fight temptation by seeing sin the way God sees it. Teaching single men God’s calling on husbands to lead, protect, and love their wives prepares them to lead, protect, and love their wives should God grant them marriage.
Some might say, “God grows us through our struggles,” or, “It’s all just theoretical until you actually experience suffering and temptation.” These are fair statements. God sanctifies us through our struggles (Heb. 12:5-12; 2 Cor. 12:1-10). Learning to suffer well doesn’t stop the shock when suffering comes, but it does soften the blow. Paul writes in 2 Timothy 3:16, “All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness, that the man of God may be complete, equipped for every good work.” Scripture is sufficient for the Christian to be complete. However much God grows us through trials and temptations, he has set Scripture as that which fully equips us for life and godliness. The rock upon which sanctification is built is Scripture, not suffering. The Bible—and the theology it teaches—is not merely sufficient to help us deal with our problems; it is sufficient to prepare us for them.
So, pastors, teach your congregation before they think they need it. Teach them the goodness of God before they question it. Teach them the nature of sin before they treat sin as a forbidden treat. Teach them the gospel week in and week out lest they forget it. Teach your congregation theology not just as a prescription to correct problems, but as preparation for them.
Church members, listen to the teaching even when you don’t need it. Take note of the sermon on suffering even though you aren’t suffering now. Heed the sermon on pride even if you feel humble. Work to apply the sermon on unity even if you think your church body is already unified. Don’t dismiss teaching just because it doesn’t coincide with your current struggles. Teaching that comes before you need it is just as much of a blessing as teaching that comes at “just the right time” because it gives you a chance to prepare for—and even prevent—future struggle. Rejoice and be thankful that theology is not merely prescriptive.
 D. A. Carson, How Long, O Lord?: Reflections on Suffering and Evil (Grand Rapids, MI: Baker Academic, 2006), 11.