In John 10:10, Jesus said, "I am come that you might have life, and that you might have it more abundantly."
1 Peter 1:8,9 tells us that although we haven't seen Jesus Christ in flesh, we still love him. We believe and that causes us to "rejoice with joy unspeakable and full of glory: receiving the end of our faith, even the salvation of our souls."
Nehemiah 8:10 says that "the joy of the Lord is your strength" so get with it and check out this awesome song!
If people without the Holy Ghost can remember to be joyful in the gift of life, how much more should we--the chosen of the Lord, the blessed among the nations, the apple of His eye--lift our voice and shout, raise the roof and dance, sing at the top of our lungs, and just be joyful in the day that the Lord has made!