Tim Keller is one of those particularly gifted and effective evangelical Christian thought leaders. He continually serves the church with his writing, his church planting efforts, his work with the Gospel Coalition, and perhaps most importantly – his pastoring.
Indeed, it would be near impossible to write a credible book about walking through pain and suffering if (a) you hadn’t walked through it yourself and/or (b) you walked closely with others during their time of trials. Suffering is a universal topic, and one that – short of Christ’s return – will never go away. It effects us all deeply, profoundly, and personally and our theology of suffering will go a long way in preparing us for when it inevitably comes for us, or someone close to us. Particularly for pastors – we need to know how to help those in suffering well. Keller, in his brilliance, succeeds in writing a challenging, informative, honest, and helpful book that everyone should read.
This book is not for the faint of heart – not only for it’s subject matter (the classic “no one wants to learn about this until we absolutely have to…”) but it’s a long book and sometimes deep sledding, but well worth it. So…let’s mush on…
Keller divides the book into three parts, and what he says unites them is the central image of suffering as a fiery furnace. Part 1: Understanding the Furnace; Part 2: Facing the Furnace; Part 3: Walking with God in the Furnace. Fire, can destroy – but if used properly does not. Things put into the furnace can be reshaped, refined, purified, and even beautified. Going thru suffering well is not a matter of technique. Suffering can refine us rather than destroy us because God himself walks with us in the fire. Ours is to orient ourselves towards God and this purpose in suffering, instead of away from him.
Keller sets a philosophical foundation by examining various cultures and how we as Americans have one of the worst and weakest views of pain and suffering of them all. the older Christian idea that we exist for God’s glory receded and was replaced by the belief that God exists to nurture and sustain us.  This is the weakness of modern secularism – if this world (and possibly the God who created it) is designed for our comfort then how can the undeniable reality of pain and suffering fit into that worldview. It can’t.
Even the professional mental, psychological, social, civlil, health experts are only there to not help us deal with the big questions (because they can’t) of “Why is suffering here? How do I deal with it?” their job is the alleviation of the pain by the removal of as many stressors as possible.  This is a major premise to understand and I was delighted to see Keller include it early on in the book. Christianity comes out as the only worldview that answers the big questions of pain and suffering – and empowers it’s people to sit in the midst of this world’s sorrows, tasting the coming joy. 
At the end of each chapter is a story detailing, sometimes in quite painful detail, the sufferings encountered by “everyday” people. These are powerful, emotional, life-applicational evidence of how a biblical worldview can give strength for today and bright hope for tomorrow.
One of the things the I found most helpful in the book’s first part was how Keller pointed out that sorrow is not to be denied, but rather Christians do not see grief as a useless thing to be suppressed at all costs. Not all weeping proceed from unbelief or weakness.  Pain and suffering is hard – let it be so. So many times we do so much damage by trying to cliche away the pain, or remove it as fast as possible – God is at work in the pain. It hurts…but there is purpose in the pain.
Keller masterfully tackles the age old conundrum of the problem of evil, surveying several theodicies, but the teeth of the argument again goes back to our Western cultural perception of suffering – the problem of evil was not widely perceived to be an objection to God until modern times.  To think that we would demand an explanation (that we couldn’t ever understand anyway) from the almighty sovereign God as to his defense for allowing pain and suffering is more than a little arrogant. Quoting Anderson – he writes “To bring God under obligation to human morality is a threat to his sovereignty.” , and again “There is a rebuke for person who, by complaining about particular events in his life, implies that he could propose to God better ways of running the universe.” Elisabeth Elliot furthers this point “God is God. If He is God, He is worthy of my worship and my service. I will find rest nowhere but in His will, and that will is infinitely, unspeakably beyond my largest notions of what He is up to.” 
As Keller points out repeatedly – just because we cannot see a logical reason why pain and suffering are allowed, it doesn’t mean that God doesn’t have any.  A better question might be why in light of our human race, does God allow so much happiness? 
Evil, suffering and pain must therefore be looked at in light of God’s big story – Creation, Fall, Redemption, Restoration. Without the hope of this eternal big picture, one can easily spend the entirety of suffering in hopeless despair. Christianity is future focused – Keller pushes on this truth by asking “Buy why could it not be that God allowed evil because it will bring us all to a far greater glory and joy than we would have had otherwise?”  One day, by his glorious grace, he will return and permanently “undo” the damage the evil has wreaked on the creation. 
A god (intentional lc ‘g’] who simply supports our plans, how we think the world and history should go is a god of our own creation, a counterfeit God. Powerfully quoting missionary Elisabeth Elliot after her husband was murdered “If God was merely my accomplice, he betrayed me. If on the other hand, He was my God, He had freed me.”  Am I serving the sovereign God of all creation or the god of my plans?
One of the greatest comforts we have as Christians is the truth that our God identifies and knows our suffering, because he himself suffered – exponentially more than we ever can. He allowed himself, in the person of Jesus Christ, to be rejected, tortured, and executed – all the while having the crushing load of emotional and spiritual darkness placed upon him, in our place on the cross.
Because of Jesus, there is always hope, even in the darkest moments of your life. 
This has powerful application in real life and the realities of pain and suffering must be faced by all believers – particularly before suffering actually hits. As Keller writes, “the stakes are high. Suffering will either leave you a much better person or a much worse person than you were before…trials will either make you or break you. But either way, you will not remain the same.” 
The truth is that God uses suffering in innumerable ways – to transform our attitude toward ourselves, to profoundly change our relationship to the good things in our live, and to strengthen our relationship to God as nothing else, it is also a prerequisite if we are going to be of much use to other people, especially when they go thru their own trials. We have to be weary of getting trapped in our suffering mindset, getting accustomed to our pain as our identity – “Suffering can turn the soul into it’s accomplice…we become complicit with the affliction, comfortable with our discomfort, content with our discontentment. This complicity impedes all the efforts to improve…even going as far as to prevent someone from seeking a way of deliverance…sometimes even from wishing for deliverance.”  Think of the crippled man by the pool in John 5…
When helping others, we must be leery of real truths applied poorly. Things expressed at the wrong time or in an unreasonable manner. Talk to anyone who has suffered and they can give you a catalog of unhelpful things that anxious friends have said to them in an attempt to act as an interpreter and find something to say to make it all better. Sufferers need to be able to weep and pour out their hearts, and not to immediately be shut down by being told what to do. Nor should we do that to ourselves if we are grieving. 
One such biblical truth is “rejoicing in suffering.” This is much different though than rejoicing “for” suffering. We need to learn to rejoice more in God and his love, but the evil was evil and would always be painful.  Likewise, we should be wary of trying to interpret, understand, and digest the whole trial at once. God never promised to give you tomorrow’s grace today. He only promised today’s grace for today, and that’s all you need. (Matthew 6:34). 
The final section of the book was extremely helpful – how do we walk thru pain and suffering? Keller points out that the walking metaphor points to the idea of progress. Again, us modern Western people view suffering as bad weather that we have to endure. We cannot lose our footing and just let the suffering have it’s way with us. We are to meet and move thru suffering without shock and surprise, without denial of our sorrow and weakness, without resentment or paralyzing fear, yet also without acquiescence or capitulation, without surrender or despair. 
As hard as it is, we must let the grief and sorrow drive you more into God. Feel the grief – the joy of the Lord can happen within sorrow. The weeping drives you into joy, it enhances joy, and then the joy enables you to actually feel your grief without it sinking you. In other words, you are finally emotionally healthy.  This is a difficult concept for modern Western people, since we think our feelings as almost holy, sovereign things.
Quoting Lloyd-Jones, he makes this point “we are not to expect God will exempt Christians from suffering and inner darkness, nor that he will simply lift the darkness as soon as we pray. Rather than expecting God to remove the sorrow and replace it with happiness, we should look for a ‘glory’ – a taste and conviction and increasing sense of God’s presence – that helps us rise above the darkness.” It is not an absence of feeling! [253-4]
This usually all boils down to trust. Evelyn Underhill said “If God were small enough to be understood, he wouldn’t be big enough to be worshipped.”
Continually citing scriptural examples, he points out Joseph – “The Joseph story tells us that very often God does not give us what we ask for. Instead, he gives us what we would have asked for if we had known everything he knows.”
Suffering should then drive us to God in prayer, John Newton said “If we are not getting much out of going to God in prayer, we will certainly get nothing out of staying away.” All of this means that if we cannot feel God in our darkest and most dry times, he is still there. Like Job, you must seek him, go to him. Pray even if you are dry. Read the Scriptures even if you are in agony. Eventually, you will sense him again – the darkness won’t last forever. .
Keller gives practical instruction in how to find God’s peace in the midst of pain and suffering – thinking, thanking, and loving – per Philippians 4:6-9.
Think hard and long about the core doctrines of the Bible. Reckon these things. [Romans 8:18; Phil 4:7-8] You will see Jesus coming to earth, suffering, dying, rising again – think primarily on the gospel. If you are a Christian today and you have little or no peace it may be because you are not thinking. Peace comes from a disciplined thinking out of the implications of what you believe.  Phil 4:6 encourages us to be thankful, for everything he sends, even if we don’t understand it. Phil 4:8 challenges us to love differently – to love not indiscriminately, but to love the right things. The final way to get the calm, the tranquility, the peace is to love him supremely.
This comes down to the heart – you will never understand your heart when things are going well. It is only when things go badly that you can see it truly.