How do we know the command to rejoice is true?

The command to rejoice is grounded in the nature of God and His promises. Paul’s exhortation in Philippians 4:4 comes from a heart filled with gratitude and a deep relationship with Christ. The basis of this joy is not contingent on our personal circumstances but rather on the unchanging character of God, who is sovereign and good. Therefore, the joy we experience is a reflection of our faith in His promises, which assures us that we can rejoice regardless of our external situations. As believers grounded in the gospel, our joy is nourished by the reality of our salvation and the imminent presence of Christ.