The dust returns to the earth as it was, and the spirit returns to God Who gave it. -- Ecclesiastes 12:7 (ESV)

Some argue this means that our spirits pre-existed before our bodies were created.

Other argue this that God created our spirits with our bodies and will collect our spirits again when our bodies die.

“Before I formed you in the womb I knew you; Before you were born I sanctified you; I ordained you a prophet to the nations.” -- Jeremiah 1:5 (NKJV)

Some argue that Jeremiah existed before he was formed in his mother's womb.

Other argue this simply mean God already had a plan for Jeremiah before he was formed in his mother's womb.

Blessed be the God and Father of our Lord Jesus Christ, who has blessed us with every spiritual blessing in the heavenly places in Christ, just as He chose us in Him before the foundation of the world, that we should be holy and without blame before Him in love, having predestined us to adoption as sons by Jesus Christ to Himself, according to the good pleasure of His will, to the praise of the glory of His grace, by which He made us accepted in the Beloved. -- Ephesians 1:3-6 (NKJV)

Some argue this means we already existed "in God", "in the heavenly places" before world was created.

Other argue this simply means God had "predestined us" before the world was created, meaning that God already had a plan for us and this does not mean that we physically pre-existed in or as part of God.

Therefore do not be ashamed of the testimony of our Lord, nor of me His prisoner, but share with me in the sufferings for the gospel according to the power of God, who has saved us and called us with a holy calling, not according to our works, but according to His own purpose and grace which was given to us in Christ Jesus before time began, but has now been revealed by the appearing of our Savior Jesus Christ, who has abolished death and brought life and immortality to light through the gospel, to which I was appointed a preacher, an apostle, and a teacher of the Gentiles. -- 2 Timothy 1:8-11 (NKJV)

Some argue this means we already existed before time began when God gave us grace.

Other argue this simply mean that by God's grace we were also part of Christ Jesus's plan to be saved.