1 Thessalonians 5:16-18 (New International Reader's Version) 16 Always be joyful. 17 Never stop praying. 18 Give thanks no matter what happens. God wants you to thank him because you believe in Christ Jesus.
Our attitude needs to reflect that we believe that God takes care of us. It needs to show our faith that He is in control, and nothing happens that is not within His will. As Christians, we should not behave as the "lost", always anxious for the next day, but instead we need to face each new day with knowledge that God's promises will all come true. Thanks to the grace and mercy provided by Jesus Christ's gift to us, we can have confidence that "our joy will be made complete(1John 1:14)".
Thank Him for allowing you to have hope in joy, and for including you in His forever family. Thank Him for the gift of Jesus and the assurance that you will be with Him forever. Always be joyful!