Who or What causes Problem of Suffering?

Suffering may be "THE RESULT OF OUR ACTIONS"

"For every action there is equal and opposite reaction." Cosmic Law of Cause and Effect

"Consider it pure joy, my brothers, whenever you face trials of many kinds,
because you know the testing of your faith develop perseverance.
Perseverance must finish its work so that you may be mature and complete,
not lacking anything" James 1:2-4

Suffering may be "THE WORK OF SATAN"

"No temptation has seized you except what is common to man. And God is
faithful; he will not let you be tempted beyond what you can bear.
But when you are tempted, he will also provide a way out so that you can
stand up under it" I Corinthians 10:13

Suffering may be "THE CHASTISEMENT OF GOD"

"When we are judged by the Lord, we are being disciplined so that we will
not be condemned with the world" I Corinthians 11:32

"And you have forgotten that word of encouragement that addresses you as sons:
"My son, do not make light of the Lord's discipline,
and do not lose heart when he rebukes you,
because the Lord disciplines those he loves,
and punishes everyone he accepts as a son"
Endure hardship as discipline; God is treating you as sons. For what son is not
disciplined by his father? If you are not disciplined, then you are illegitimate
children and not true sons" Hebrews 12:5-8