The suffering in the world is caused by the sinful ways of man. The way which we have chosen is not bringing us anything good. It brings evil. When we gave ourselves to the evil one to walk against the commandments of God, the rewards of wickedness follow us. There is no peace for the wicked. The soul that sins shall die. This implies that the soul who sins will suffer.
Choosing the path of sin is what brings the wrath of God upon the sons of men. God showed us the path of righteousness and commanded us to follow same. He sent us His son Jesus Christ to teach us his ways. We choose to ignore his calling and follow the path of sin. Now God is not happy with sinners. Suffering is the reward for our sinful ways.
John 16:33 (KJV) These things I have spoken unto you, that in me ye might have peace. In the world ye shall have tribulation: but be of good cheer; I have overcome the world.
God created a perfect world for us. He made everything and observed everything He made that it was good. We should have live in peace and perfect joy. That was God's plan for us. Let us repent from our sinful ways and return to God. Let us reject the works of the flesh. Let us obey the commandments of God. He will send us from all our troubles. God’s way is the only way out of the suffering in the world.
Suffering is as a result of man's evil works
Sin brings the suffering