BANG!!!.....And everything exploded into being, so the story goes.  If this Big Bang event is your personal view of creation, without a divine creator or God in the picture, then ALL of us have no purpose.  The great news is you cannot have an effect without a cause and something does not come about from the build-up of nothing.  Nothing times nothing is still nothing (0x0=0).  There was a cause.  It was divine.  And because their is a Creator, there is purpose.  

Now the question becomes which creation story of which faith gives us the most purpose.  Purpose is the reason for which something exists or is made.  I choose Christianity and the purpose God supplies.

For by him all things were created: things in heaven and on earth, visible and invisible, whether thrones or powers or rulers or authorities; all things were created by him and for him. - Colossians 1:16

In the beginning was the Word, and the Word was with God, and the Word was God.  He was with God in the beginning.  Through him all things were made; without him nothing was made that has been made.  In him was life, and that life was the light of men.  The light shines in the darkness, but the darkness has not understood it. - John 1:1-5

These verses leave no doubt about the plan of God and how IT all started.  Humanity had the right kind of relationship with God for two chapters in Scripture (Genesis 1 & 2).  There are no definite years equated with the time that elapses within these two chapters.  However, I personally believe that a massive amount of time transpired due to the number of years people like Methuselah lived - Altogether, Methuselah lived 969 years, and then he died. (Genesis 5:27).  And this individual was born and lived after The Fall (after the relationship with God had been damaged), so people before The Fall may have lived even longer.  

During the lengthy "Blissful Time" (pre-fall) God had a specific purpose for humanity - steward of the earth, but especially a region called The Garden of Eden.  

Now the LORD God had planted a garden in the east, in Eden; and there he put the man he had formed. 9 And the LORD God made all kinds of trees grow out of the ground--trees that were pleasing to the eye and good for food. In the middle of the garden were the tree of life and the tree of the knowledge of good and evil. 10 A river watering the garden flowed from Eden; from there it was separated into four headwaters. 11 The name of the first is the Pishon; it winds through the entire land of Havilah, where there is gold. 12 (The gold of that land is good; aromatic resin and onyx are also there.) 13 The name of the second river is the Gihon; it winds through the entire land of Cush. 14The name of the third river is the Tigris; it runs along the east side of Asshur. And the fourth river is the Euphrates. 15 The LORD God took the man and put him in the Garden of Eden to work it and take care of it. - Genesis 2:8-15

Now the LORD God had formed out of the ground all the beasts of the field and all the birds of the air. He brought them to the man to see what he would name them; and whatever the man called each living creature, that was its name. - Genesis 2:19

Then God said, "Let us make man in our image, in our likeness, and let them rule over the fish of the sea and the birds of the air, over the livestock, over all the earth, and over all the creatures that move along the ground."  So God created man in his own image, in the image of God he created him; male and female he created them.  God blessed them and said to them, "Be fruitful and increase in number; fill the earth and subdue it. Rule over the fish of the sea and the birds of the air and over every living creature that moves on the ground." - Genesis 1:26-28

Our purpose has increased and changed slightly since that "Blissful Time".  We made the ultimate mistake with the most precious of relationships, BUT God redeemed that relationship through His Word made flesh, Jesus. Now our purpose is to spread that awesome Redemptive news and be God's Messenger today to deliver the faith activated, purpose driven opportunity that only Father God granted through Jesus The Christ.  Speaking through His Disciples down through the ages, Jesus says to True Believers in Christ everywhere - 

"Go into all the world and preach the good news to all creation." - Mark 16:15

More good news here - you do not have to have a degree to do this!  The cast of characters that Jesus called to be His Disciples did not have degrees, nor were they known as "learned" men.  Most of the Disciples were fishermen (Peter, James, John, and Andrew).  There was a tax collector - Matthew, a treasurer - Judas, and Simon the Zealot was a political activist within the group of twelve.  Since Jesus said, "Follow me" and "Go into all the world and preach" to this bunch, I suddenly feel more empowered by the Holy Spirit, especially with the kind of upbringing I had, occupation I have, and the kinds of resources we have now-a-days.  I was brought up in the "way I should go", I have a job in "the world marketplace" (as opposed to the church), and I have technologies at my fingertips to share The Word (like this).  I am not a preacher/teacher by trade or training, but I believe it is my spiritual gift.  Ah, there is purpose again.  A gift from God by the Holy Spirit SO THAT.....I and we, as Believers in Christ, can fulfill our purpose which is to be in line and act out His purpose(s) for our lives spelled out in His Word.  Which according to Mark 16:15 is to "Go...and preach the good news to all"!