All the days of the afflicted are evil, But he who is of a merry heart has a continual feast. (Proverbs 15:15 NKJV)
Affliction comes to every child of God. It's a well-known fact of life. If we follow Jesus, we will find affliction in many shapes and forms. God uses these to sharpen us, strengthen our faith and patience, and to mold our character. However this does not mean that these afflictions are sent upon us by God Himself.
The world is a dark place because of the wicked actions of sinful people. God gave us the earth, (Psalm 115:16) and the terrible things that happen upon it are results of sin. So it makes sense to me that this verse would say "all the days of the afflicted are evil". Affliction is what we receive because we live in a world full of evil. The Amplified Bible says it well:
All the days of the desponding and afflicted are made evil [by anxious thoughts and forebodings], but he who has a glad heart has a continual feast [regardless of circumstances]. (Proverbs 15:15 AMP)
Praise God that even though hard times come against us, we still have hope! God promises to deliver us, strengthen us, and give us joy through the difficult times. When He puts His joy in our hearts, we have a continual feast: a continued fulfillment of peace and gladness. How awesome is it to know that our Father in heaven loves to give GOOD gifts to His children? How wonderful it is to know that even through the dark times the world throws at us, we still have a good God to carry us through.