"Rejoice in the Lord always, and again I say rejoice!" (Phil.4:4)
We are called to rejoice IN THE LORD, not in circumstances. Happiness depends on happenings; but, we can rejoice in the Lord.
We'll look at 3 reasons, among many many more, to rejoice in the Lord.
We can rejoice because of DIVINE
When Gabriel met Mary in Luke 1:28, he greeted her saying, "Greetings, you who are highly favored! The Lord is with you.” Because of God's favor, Mary could say, "My soul glorifies the Lord and my spirit rejoices in God my Savior, for he has been mindful of the humble state of his servant. From now on all generations will call me blessed, for the Mighty One has done great things for me—holy is his name." (46-49).
The favor of God protected, positioned, and promoted Joseph. God's favor in Christ Jesus is the reason why we can rejoice, because He doesn't treat us as we deserve but treats us as highly favored.
We can rejoice everyday again and again because of His favor every moment.
Jesus said in John 15 that if we abide in Him then we'll be fruitful. Right connection and communion brings fruitfulness. Barrenness brings sadness and sorrow; but, fruitfulness brings rejoicing. We can be joyful because God has plans of success and fruitfulness for us.
Back to Philippians 4, the Bible calls us to cast all our burdens on Christ and experience the freedom of truth and absolute reliance. Those who cast all their burdens on the Lord can be carefree, because He has promised to take care of us!