For all of humanity, many have struggled to understand and find purpose for their lives - people instinctively know that they can find joy in knowing that they are bringing value into the world. Simply said, knowing you are on task brings you great joy.
For us believers, it should be straightforward...we exist to glorify God because He has a purpose for us all. While one might quibble about what "glorify" means for us specifically, one thing is clear - we glorify God by knowing Him, loving Him, trusting Him, and following Him (among many things we must do to be in relationship with God).
This is reinforced in Nehemiah after those who hear the word of God are joyful:
12 Then all the people went away to eat and drink, to send portions of food and to celebrate with great joy, because they now understood the words that had been made known to them.
My Prayer: Lord, I know you made me for your glory and I have seen your work in my life and I am amazed at your power and might. Yet I am humbled because I cannot see sometimes how a sinner like myself can be used by You. Forgive me for not trusting in you to work through me. Help me know you more, love you more, trust you more, and follow you more.