An important doctrine in LDS theology is that we existed before we were born to mortality. We believe that God the Father is the actual father of our spirits. When we were born, our spirits joined with our bodies to form the soul that we now have. There are many scriptures in the Bible that give us information about our life as spirits. We also have additional scripture, but I will focus here on the scriptures found in the Bible.
--1 The burden of the word of the Lord for Israel, saith the Lord, which stretcheth forth the heavens, and layeth the foundation of the earth, and formeth the spirit of man within him. (Zechariah 12:1)
--We are the spirit children of God:
--28 For in him we live, and move, and have our being; as certain also of your own poets have said, For we are also his offspring. (Acts 17:28)
--9 Furthermore we have had fathers of our flesh which corrected us, and we gave them reverence: shall we not much rather be in subjection unto the Father of spirits, and live? (Hebrews 12:9)
--16 The Spirit itself beareth witness with our spirit, that we are the children of God: (Romans 8:16)
-- We shouted for joy at the creation of the world, and the plan that was presented to us.
4 Where wast thou when I laid the foundations of the earth? declare, if thou hast understanding.
5 Who hath laid the measures thereof, if thou knowest? or who hath stretched the line upon it?
6 Whereupon are the foundations thereof fastened? or who laid the corner stone thereof;
7 When the morning stars sang together, and all the sons of God shouted for joy?
Some were ordained to perform certain duties in this life:
The Lord told this to the prophet Jeremiah about his fore-ordination in the spirit world:
-- 5 Before I formed thee in the belly I knew thee; and before thou camest forth out of the womb I sanctified thee, and I ordained thee a prophet unto the nations. (Jeremiah 1:5)
--9 Who hath saved us, and called us with an holy calling, not according to our works, but according to his own purpose and grace, which was given us in Christ Jesus before the world began, (Timothy 1:9)
This one speaks of the Savior's foreordination:
19 But with the precious blood of Christ, as of a lamb without blemish and without spot:
20 Who verily was foreordained before the foundation of the world, but was manifest in these last times for you,
(1 Peter 1:19,20)
--Some spirits chose not to follow God's plan, and kept not their "first estate". They chose Satan's plan
-- 6 And the angels which kept not their first estate, but left their own habitation, he hath reserved in everlasting chains under darkness unto the judgment of the great day. (Jude 1:6)
-- 7 And there was war in heaven: Michael and his angels fought against the dragon; and the dragon fought and his angels, (Revelations 12:7)
We have additional scripture in the Pearl of Great Price, Doctrine and Covenants, and Book of Mormon that give more information about our pre-existent life. But I am thankful for what the bible teaches us about our spirit life, and the plan of salvation.