“All suffering is either a direct or an indirect result of sin.”

Don’t agree yet? Let’s discuss this deeply, and please give me the grace allow me to explain it as I see it.

Firstly, let’s take the suffering of our Lord Jesus Christ. Everyone who loves Him and knows Him knows that He was totally sinless, and that He didn’t deserve any suffering at ALL. 
Yet, I would say that His suffering was a both a DIRECT and an INDIRECT result of sin. How can this be, you say? Well, it wasn’t because HE was sinning (of course), but mainly because He was handed over into the hands of sinners who wanted to murder Him brutally for so called blasphemy. His suffering was a direct result of their sin in real time in this sense, for they were there banging the nails into His hands, yelling “crucify Him!”. He was sinned against by them, for He didn’t deserve it, and their sins cause Him great physical suffering.
Having say that, His suffering was also an indirect result of sin, for He went to that cruel cross because of a prophecy made by the Father in Genesis 3, fulfilling the prophetic curses placed on Adam, Eve and the snake. Indirectly, their collective sins instigated and manifested His suffering thousands of years later on the cross, for He is mystically the ‘Lamb slain before the foundation of the world’. The whole narrative of the bible is mainly about this one event, the Messiah coming to both suffer for the sins of the world and to also vanquish the power of death that His great spiritual enemy, satan, had had up until that point. He gloriously won the victory over him at Calvary, yet it must still be recognised that the devil was the initiator of sin in the garden as tempter, and saw to it that both Judas and Peter would betray Him. He was the tempter in the desert during that enormous fast. He also was technically the god of the Romans who crucified Him, and no doubt he made personally sure that it was as excruciating as possible. The suffering of Christ was directly the result of the devil’s wickedness, right from the start.
Of course, if sin had never entered into the world via humanity succumbing to temptation in the first place, the suffering of Christ would never have been necessary, right? Still, the devil’s sins must still have been fought against, and just as with any war, there is a measure of suffering, whether physical or spiritual.

And still it must be said that also indirectly (but also strangely, directly), His suffering was caused by each of OUR own sins – we are also the ones hammering in the nails and spitting in His face, yelling “crucify Him”, every time we disobey the Father and strive for our own kingdom over His.

‘Ok then, I can get that’, you might say. But what of innocent young children born with bone cancer, or something equally as horrific? Surely their suffering isn’t caused by sin? They have done nothing to deserve it!
Regardless of whether someone deserves to suffer or not, I would still reply that the suffering of innocents like these is still indirectly caused by sin, because it all goes back to man’s first rebellion against God in the garden of Eden, who had promised death to His children should they disobey Him about eating the fruit from that fateful tree. The entire creation groans under the heavy weight of our first parent’s disastrous mistake, and when sin entered into the world, so did corruption, and sickness of every kind along with it. This is true for all handicaps, diseases and illnesses, for they are simply symptoms of a looming eventual death. Indirectly, the suffering of all of it comes from that one first disobedience, where sin (and therefore death) entered into physicality. 
Put it like this. From the time we are first conceived, the clock starts counting our days, for all life has an end, because death is the wages of sin, and we are all sinners. Children are ‘conceived into sin’ (psalm 51) and the Lord ‘traps us in disobedience so He can have mercy on us’ (Romans 11). Creation’s suffering is a result of that one major transgression in the garden; the timer was turned and the sands began to run out. 
Do animals sin? Not that they are responsible for, no. Do they die? Yes. Why? Because death entered the world because of sin. Why do any beings die? Physically, because of diseases like bone cancer (for example), but spiritually because of the indirect cause of the sin of Eden that caused the physical ailment. Does that mean they deserve it? Not necessarily at all, no. Yet again I emphasise that all the suffering is still a result of sin, in some fashion.

So then, this realisation that sin is responsible for all the suffering in the world SHOULD lead us with the incentive to want to try and lead a holy life. Why? Well, it’s not because we won’t suffer ourselves; surely if we live like the Master, we’ll die like Him too… and then be raised with Him to glory, of course, for the time is coming when all suffering will cease for those who are ‘in Christ’.
No, the reason we should want to live holy is because we should want to imitate the Lord exactly, being a blessing to the world, rather than adding more curses to it. For if we are sinning rather than living a holy life, we immediately directly affect others around us negatively; but if we were to go deeper than that, we INDIRECTLY add to the exponential cost that sin has already had spiritually on the entire human race, and creation as a whole. If we are living unholy, we advocate, propagate and condone suffering and death, rather than slay it with righteousness (which is what Christ came to do). Living unholy means that we choose to be an enemy of God, who wants to restore everything to the way it was before Eden, if not make it much better, and there are major consequences for that, both personally and collectively.

I have always said that the closer one gets to holiness, the more one is aware of sin. The Lord reveals to us over time just how deep it goes, and how far we all fall short, even when we think we stand. Choosing a life of holiness is no guarantee that you’ll never suffer in this life, but in many ways, to choose it is to alleviate suffering on others (as well as personally) in many ways. Lives of self sacrifice are bountiful in good spiritual fruit that sooth and lessen the suffering of others, even indirectly having a bearing of the suffering of Christ at our hands.

He asks us to stop sinning and pick up our own crosses, partly to help Him bear the huge weight that sin has on our world (and no, I’m not saying we can save ourselves by adding works to His sacrifice – just saying we can lessen His suffering via our personal volition to be done with sin and work with Him to help others also find a holy way of living, teaching them to also self sacrifice).