How do I prove that our souls existed even before we were conceived?

Jeremiah 1:1-5
1:1 The words of Jeremiah the son of Hilkiah, of the priests that were in Anathoth in the land of Benjamin:
1:2 To whom the word of the LORD came in the days of Josiah the son of Amon king of Judah, in the thirteenth year of his reign.
1:3 It came also in the days of Jehoiakim the son of Josiah king of Judah, unto the end of the eleventh year of Zedekiah the son of Josiah king of Judah, unto the carrying away of Jerusalem captive in the fifth month.
1:4 Then the word of the LORD came unto me, saying,
1:5 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.

Ecclesiastes 12:6-7
12:6 Or ever the silver cord be loosed, or the golden bowl be broken, or the pitcher be broken at the fountain, or the wheel broken at the cistern.
12:7 Then shall the dust return to the earth as it was: and the spirit shall return unto God who gave it.

Ephesians 1:4-6
1:4 According as he hath chosen us in him before the foundation of the world, that we should be holy and without blame before him in love:
1:5 Having predestinated us unto the adoption of children by Jesus Christ to himself, according to the good pleasure of his will,
1:6 To the praise of the glory of his grace, wherein he hath made us accepted in the beloved.

Revelation 17:8
8 The beast that thou sawest was, and is not; and shall ascend out of the bottomless pit, and go into perdition: and they that dwell on the earth shall wonder, whose names were not written in the book of life from the foundation of the world, when they behold the beast that was, and is not, and yet is.
KJV

John 3:3-13
3 Jesus answered and said unto him, Verily, verily, I say unto thee, Except a man be born again⁵⁰⁹, he cannot see the kingdom of God.

4 Nicodemus saith unto him, How can a man be born when he is old? can he enter the second time into his mother's womb, and be born?

5 Jesus answered, Verily, verily, I say unto thee, Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God.

6 That which is born of the flesh is flesh; and that which is born of the Spirit is spirit.

7 Marvel not that I said unto thee, Ye must be born again⁵⁰⁹.

8 The wind bloweth where it listeth, and thou hearest the sound thereof, but canst not tell whence it cometh, and whither it goeth: so is every one that is born of the Spirit.

9 Nicodemus answered and said unto him, How can these things be?

10 Jesus answered and said unto him, Art thou a master of Israel, and knowest not these things?

11 Verily, verily, I say unto thee, We speak that we do know, and testify that we have seen; and ye receive not our witness.

12 If I have told you earthly things, and ye believe not, how shall ye believe, if I tell you of heavenly things?

13 And no man hath ascended up to heaven, but he that came down from heaven, even the Son of man which is in heaven.
KJV

NT:509 - again
anothen (an'-o-then);
from NT:507; from above; by analogy, from the first; by implication, anew:
KJV - from above, again, from the beginning (very first), the top.