Blessed are you when men hate you, and when they exclude you, and revile you, and cast out your name as evil, for the Son of Man's sake. Rejoice in that day and leap for joy! For indeed your reward is great in heaven, for in like manner their fathers did to the prophets.
When we are persecuted for the Master's sake, we don't put on a sad countenance and wrinkle our brows. No one will be drawn to our Spirit with that attitude. When we suffer, we are to rejoice.
Joy is not the same as happiness. Happiness is dependent upon circumstances. If the circumstances are unfavorable, the happy person becomes sad. Joy is different. Joy flows right on through trouble and darkness. Persecution and opposition does not destroy this joy. It continues to flow because it is an unceasing fountain bubbling up in the heart; a secret spring that the world does not understand. The Lord gives His people perpetual joy when they walk in obedience to Him.
This joy is fed by the Word of God.
Your words were found, and I ate them; and Your word was to me the joy and rejoicing of my heart; for I am called by Your name, O Lord God of hosts.
There are hundreds of "rejoicing texts" in the scriptures. "Be glad in the Lord," "Rejoice greatly," and "Shout for joy." If our Father took the trouble to tell us hundreds of times to be glad and rejoice, He must want us to do it. Look not to the world or circumstances for joy. Look to Christ and His Word for your joy.