"Thy words were found, and I did eat them; and thy word was unto me the joy and rejoicing of mine heart: for I am called by thy name, O LORD God of hosts" (Jeremiah 15:16).
People today seem always to be looking for fun or entertainment, but it is significant that "fun" is never mentioned in the Bible, so it is evidently not considered to be a very significant part of the Christian life. The word "entertain" is used to speak of hospitality, and such activities as "play" and "reveling" only receive condemnation. ("Playing" is appropriate for children and animals, of course.)
Christians, however, have something far better than worldly fun--they have heavenly joy! This is the unique privilege of the redeemed, and there are many channels through which this joy can be experienced.
First of all, Christian joy comes through the Word. As even Jeremiah ("the weeping prophet!") could say: "Thy word was unto me the joy and rejoicing of my heart," as in our text. Then we rejoice in God's great salvation: "I will greatly rejoice in the LORD, my soul shall be joyful in my God; for He hath clothed me with the garments of salvation" (Isaiah 61:10).
There is great joy also in the privilege of prayer and having our prayers answered: "Hitherto have ye asked nothing in my name: ask, and ye shall receive, that your joy may be full" (John 16:24). Christian service and witnessing is a source of tremendous joy when its fruits are finally seen. "They that sow in tears shall reap in joy. He that goeth forth and weepeth, bearing precious seed, shall doubtless come again with rejoicing, bringing his sheaves with him" (Psalm 126:5-6).
And there is much, much more! "Rejoice in the Lord alway: and again I say, Rejoice" (Philippians 4:4). After all, we know personally the very Creator of all that is good, "in whom, though now ye see Him not, yet believing, ye rejoice with joy unspeakable and full of glory" (I Peter 1:8). HMM