For even the Son of man came not to be ministered unto, but to minister, and to give his life a ransom for many.–Mark 10:45
If anything, the Bible is a realistic book. It shows the ups and downs of those who serve God. Like us, sometimes they had good days and sometimes they had bad days (humanly speaking). The Bible doesn’t attempt to hide the humanity of its subjects or the realities of life in a fallen world. But surprise!–the Bible demonstrates a new reality with which the world is not familiar: It is possible to find joy in service, even when life is hard.
When the Bible says “rejoice always,” that isn’t a chant for a Christian pep rally. It’s part of the reality of the kingdom of God. For instance, when Paul and his companions were driven out of Pisidian Antioch by the Jews after preaching the Gospel there, “the disciples were filled with joy and with the Holy Spirit” (Acts 13:52). Joy is part of the new reality of life in the Spirit since joy is part of the fruit of the Spirit (Galatians 5:22). When we are serving Christ, whether the service is easy or hard, there is joy to be found in it because it is the Spirit who directs it.
The surest remedy for discouragement is joy, and joy overflows in Spirit-led service for Christ. That is the new reality of life in the kingdom of God.–From Turning Point
Joy in the Lord should be the loftiest joy.