In Philippians chapter two, Paul gave us examples for living the Christian life. He pointed out a sign of unbelief in Christians has to do with grumbling and arguing. Do all things, he says, without grumbling and questioning (2:14 ASV), because questioning (or grumbling) portrays a doubtful believer, someone who is having trouble believing what God is telling him. I think Paul was relating to the unbelieving Israelites who complained to Moses and to God (1 Cor.10:10).
Rejoicing is the mark of one who has learned to believe. I have heard the definition of a Christian as: someone who is completely fearless, continually cheerful, and constantly in trouble. It is the continual rejoicing during times of trouble that marks the Christian.
Paul was in jail when he reminded the Philippians (3:1) that true joy is not dependent upon circumstances. The word "rejoice" is a verb. That means it is something we do. "Joy" is a noun. A noun is something we have. We are to rejoice regardless of how we feel, because the truth is in our born-again spirit, we always have joy.
One way to rejoice is to offer Him our thankgiving and praise.
Hebrews 13:15, By him therefore let us offer the sacrifice of praise to God continually, that is, the fruit of our lips giving thanks to his name.
Continually: Gk. verb diapantos, dee-ap-an-tos' A continuous, habitual action.
My Confession: I thank You Jesus! Lord, I rejoice in knowing that You are always faithful to Your word. Jesus, You are my wonderful saviour and healer. I will continue to praise You.
My Confession: Lord, my situation does not dictate to me when to praise Your holy name. My circumstanses change, my feelings fluctuate, but I will always rejoice in You, Lord.