The meaning of suffering

In this life, suffering is part of the territory.
We must learn to deal with it.
God told Cain that sin was crouching at his door and that he must “master it.”
Cain did not oppose the bitter/resentful part of himself. Rather, he took his bitterness out on someone else—his brother. He killed Abel.
People who allow the bitter badness of this life to defeat their attitude--those people end up taking their frustration out on other people.
A person who has been corrupted by his own bitterness/anger will likely turn to destructive behavior to express his/her frustration. That person may concoct an evil plan to hurt/ kill some person who has gotten in their way. Or worse yet, that person may go ballistic, sociopathic, and decide to go on shooting spree before turning the gun on himself.
If we do not cope with suffering, if we do not contend the resulting resentment, it will master us, instead of us mastering it. 
If and when that happens—if the urge to extract vengeance takes control of us—instead of us controlling it—we buckle under the pressure and things get worse.
Such evil also manifests collectively in historical ways. In the 1930’s-40’s, the Nazis took out their bitterness agains other Europeans who had previously defeated them militarily. They also embodied depravity by inflicting their hyped-up vengeance against Jews, because they entertained the lie that Jews were responsible for their social/cultural failures.
The fundamental struggle in this life—both individually and collectively— is to somehow accept that shit happens (we will have a certain amount of suffering) and then contend against our own bitterness, and thereby defeat the urge to take out our troubles on others.
This requires a certain acceptance of suffering. No person escapes it entirely.
Understand that suffering is a part of life. Trouble is built in, because (in my view) opposing it builds godly character.
So we must overcome the urge to blame others for our troubles. We need to take responsibility for our own lives—our own failures, as well as our own successes.
But it’s not easy; we need help.
The follower of Christ realizes that we cannot undertake that battle without our Creator’s help.
Like it or not, God has constructed this life in such a way that we must admit our inadequacy and turn to Him for help, so as to overcome the destructive influences of this world instead of turning those destructions on other people.
And he has given us his Son, who contended with evil and suffering to the nth degree—to the very end of his own tortured life—in order to demonstrate that suffering is not meaningless. It’s just part of the territory in this world, especially if we resolve to do any "good."
Furthermore, the inevitable death that is the result of this troublesome life--that dreaded death lands us--if you can allow yourself to believe it-- in a place that is even greater than this present life—resurrection into eternal life.
So accept that this life is difficult, and suffering is part of the territory, and don’t take out your anger on others. Do unto them what you would have them do unto you.
Life ain't no bowl of cherries. That much is plain to see. It's no walk in the park.
Deal with it. Master it. Turn it over to the one who endured the absolute worst suffering as a consequence of his living  life totally void of destructive resentment. Otherwise you may hurt yourself badly; and if that is not enough you may hurt someone else. Don’t go down that path.
Rather,  when you find yourself at the crossroads of bitterness and injustice, take up the deepest challenge that this life presents. Accept your suffering  willingly. Endure, persevere while manifesting love and goodwill, and thereby defeat the urge to do wrong to others and to yourself.

King of Soul