The search for purpose in life has puzzled people for thousands of years because we usually look in the wrong place: ourselves.  While society and self-help books disagree, you won't discover purpose by looking within yourself.  Only God, the creator of life, can reveal your purpose here on earth. 

"Everything, absolutely everything, above and below, visible and invisible. . .  everything got started in Him and finds its purpose in Him"  (Colossians 1:16, The Message).

To know God's purpose for your life means you need to know God.  God desires to have a relationship with you and show you your purpose in life, but sin has separated man from God.  In order to restore man's relationship with God, he sent His Son, Jesus Christ, to die for you and pay the penalty for your sin.  Because the penalty for sin has been paid, you can have a relationship directly with God but it requires an individual response from you to receive it.  To accept Jesus into your heart, you have to acknowledge that:

We are sinful: 
"For all have sinned and fall short of the glory of God" Romans 3:23

Be willing to repent and turn away from sin:  
"For the wages of sin is death"  Romans 6:23

Believe that Jesus Christ died for you on the cross:  
"But God demonstrates His own love for us in this:  While we were still sinners, Christ died for us"  Romans 5:8

You must receive Him:

"Yet to all who receive Him, to those who believed in his name, He gave the right to become children of God"  John 1:12

Receiving Christ into your heart is as simple as asking Him to come into your life.  You could pray a simple prayer like this:

"God, I know that I am a sinner and need Your forgiveness.  I believe that Jesus Christ died for my sins.  I want to turn from my sins.  I invite Jesus Christ to come into my heart and life as my personal Savior and Lord of my life.  In Jesus name, Amen"

When you receive Christ into your heart you become a child of God.  you can talk to Him in prayer at any time about anything.  The Christian life is a personal relationship with God through Jesus Christ