Pain, suffering and trials exist because sin exists

Then God said, “Let us make mankind in our image.”         Genesis 1:26

And God saw everything that he had made, and behold, it was very good.        Genesis 1:31

“You may surely eat of every tree of the garden, but of the tree of the knowledge of good and evil you shall not eat, for in the day that you eat of it you shall surely die.”         Genesis 2:16-17

When the woman saw that the fruit of the tree was good for food and pleasing to the eye, and also desirable for gaining wisdom, she took some and ate it. She also gave some to her husband, who was with her, and he ate it. 7 Then the eyes of both of them were opened, and they realized they were naked.    Genesis 3: 6-7

Disease and death exist because sin exists

Mankind is Also Tempted to Sin not Just Bent Towards Sin

He was a murderer from the beginning, and does not stand in the truth, because there is no truth in him.  When he lies, he speaks out of his own character, for he is a liar and the father of lies.        John 8:44

God works in good times and He works through painful, times of suffering

For as the heavens are higher than the earth, so are my ways higher than your ways and my thoughts than your thoughts.             Isaiah 55:9 

And we know that in all things God works for the good of those who love him, who have been called according to his purpose.             Romans 8:28 

Count it all joy, my brothers, when you meet trials of various kinds, for you know that the testing of your faith produces steadfastness. And let steadfastness have its full effect, that you may be perfect and complete, lacking in nothing.         James 1:2-4

The God of all comfort…comforts us in all our affliction, so that we may be able to comfort those who are in any affliction, with the comfort with which we ourselves are comforted by God.    2 Corinthians 1:4

For I know that my Redeemer lives, and at the last he will stand upon the earth.          Job 19:25

33 “I have told you these things, so that in me you may have peace. In this world you will have trouble. But take heart! I have overcome the world.” John 16:33