I see this post is a bit old, but I came across it while preparing for a discussion on the pre-existence with the 12-18 year old young men in our LDS congregation. Since the very first reply above raises the LDS doctrine, I thought I would round out the post by noting a few points about that doctrine. 

 1. We are all God's children, and he created us spiritually before we came to this earth.
 2. We lived in heaven with God our Father for quite some time, learning line upon line, precept upon precept.
 3. The Father presented His plan to send us to earth into mortality to provide us the experience necessary to continue to grow. The plan is known as the Plan of Salvation or the Plan of Happiness.
 4. This plan included the Atonement of Jesus Christ, without which, we would be unable to return to God's presence.
 5. One of the signature characteristics of the children of God is their Agency, or their freedom to choose, which was bestowed upon us by God at the time of our spiritual creation. God permitted us to choose whether we would follow Christ, the leader of His plan, or Satan, who had presented a competing, though ultimately nihilistic, plan. Every soul who enters mortality chose in the pre-existence to follow Christ and accept the Father's plan.
 6. A veil of forgetfulness was placed over our minds, to give emphasis to the faith that is necessary to grow according to the Father's plan for us. Yet the Father, whose entire purpose is to help us return to Him, gives us the Holy Spirit who whispers to us from time to time that we might, through trial and experience, through faith in Christ, return again, much improved, to our Father's presence.

This true doctrine gives depth and meaning to all of the Bible versus cited above.

To learn more: 

 - http://mormon.org/plan-of-happiness/
   
 - http://www.lds.org/scriptures/pgp/abr/3.22-28?lang=eng