Solomon said in Proverbs 15:15, "All the days of the afflicted are evil: but he that is of a merry heart hath a continual feast." The Hebrew word which is translated "afflicted" could be better translated "depressed". Reading again Proverbs 15:15, "All the days of the depressed person are evil: but he that is of a merry heart has a continual feast." In other words, the depressed person sees all his days as being evil, but the person who chooses to have a merry heart has a a continual abundance of good things to eat and enjoy.
The question is, "How can one have a merry heart, even in the midst of problems?"
First, one must understand that God is ultimate in control. He is the potter and we are the clay. He is there refiner and we are the gold. He is the wine maker and we are the wine. He is the builder and we are the building material.
Second, one must understand that adverse circumstances will come. Jesus said, "In the world ye shall have tribulation: but be of good cheer; I have overcome the world".
Third, we must understand that God desires to work all things together for our good, even those we might consider the bad ones.
Once we come to see and believe these three truths, we must CHOOSE by faith to have a merry heart. It is then that we experience a continual feast.