" Human nature tends to turn negative in difficult times. But the Scripture tells us to do just the opposite: “Count it all joy when you fall into various trials” (James 1:2 NKJV). That doesn’t seem to make sense to some people. “You mean we’re supposed to be joyful and glad-hearted in the middle of tough times?” they ask. Yes, that’s right, because when you lose your joy, you lose your strength.
You need your strength more than ever in the difficult times, and your strength is dependent on your joy. When you’re facing a financial crisis, dealing with an illness, going through a breakup in a relationship, or raising a rebellious child, you need your strength. If you go through those challenges feeling negative, bitter, and discouraged, you will not have the vitality to stand strong and fight the good fight of faith.
You can keep your joy by knowing that on the other side of each test is promotion. On the other side of every setback is opportunity. On the other side of every offense is growth. The difficulties you face are not there to defeat you. They are there to increase you.
Just keep reminding yourself, Even though this is hard, even though I don’t understand it, even though it’s not fair, I’ll keep a good attitude and stay full of joy, knowing that this is not setting me back. It is setting me up for God to bring me through to the other side of this in an even better position. "

― Joel Osteen , Every Day a Friday: How to Be Happier 7 Days a Week