"I know that there is nothing better for men than to be happy and do good while they live" (Ecclesiastes 3:12, NIV).
"As the Father has loved me, so I have loved you. Now remain in my love. If you obey my commands, you will remain in my love, just as I have obeyed my Father's commands and remain in his love. I have told you this so that my joy may be in you and that your joy may be complete" (John 15:9-11, NIV).
Rubel Shelly has a good piece at http://www.rubelshelly.com/content.asp?CID=19803 about enjoying life to the glory of God.
Speaking of enjoying life, my wife Janet has written a short post on her blog about our 5-year old son Christopher leading a song at the Contact Church last Sunday morning. It may be read at http://blog.360.yahoo.com/blog-CLo4pSAlcaXgi2dhLKNo?p=84. I'm not sure that anyone enjoys life more than our son.