I Thessalonians 5:16-18
16 Rejoice evermore.
17 Pray without ceasing.
18 In every thing give thanks: for this is the will of God in Christ Jesus concerning you.
Only Christians can truly rejoice with a joy that is “unspeakable and full of glory,” and the secret to experiencing this perpetual rejoicing spirit is to follow Paul’s instruction regarding a prayerful spirit, “praying always,” “without ceasing,” and Paul’s instruction regarding a grateful spirit, “in every thing give thanks.” This truly is the will of God for the believer, and without a relationship with Christ, it is not possible.