God created us for HIMSELF. We were created for praise! Each and every one of us has something we are supposed to be doing on earth. We all have a "calling." Everyone is not called to be behind the pulpit, but we are all "ministers" of Christ. My ministry might be behind the pulpit. Your ministry might be at Wal-Mart or at the clothing store you own, etc,... We are ALL called to share the Gospel; the Good News of Jesus Christ.
Many people come to me and say, "I don't know my purpose. Why am I here?" The first thing I tell them is, "you are not an accident!"
I don't care what the circumstances surrounding your birth were, you made it here. You have a purpose. That purpose is to glorify our Abba Father (God)!
The only way we discover who we really are is to first receive Jesus Christ as our Saviour. When we do this, His Holy Spirit comes to live in us. The more time we spend talking to God (prayer), and the more time we spend studying God's Word (Bible), the more in tune we become to the Spirit. As you hear many Christians say "They felt led to do this or that." These are called unctions from the Holy Spirit. Even if you don't hear God audibly, He speaks to you through these leadings.
God speaks to you through His written Word (Bible). Also, the more time you spend in prayer, talking to God, He will answer your questions. Sometimes, God sends people with the answers to the questions you've asked Him, or with things you need. These people don't always have to be prophets. They may not even be Christians! God can use anyone He wants to.
God loves us so much. We glorify Him when we are doing what He created us to do, and being who He created us to be. You want to know who you are and why you are here. Spend time with God!