Regeneration

But because of his great love for us, God, who is rich in mercy, made us alive [quickened us] with Christ even when we were dead in transgressions – it is by grace you have been saved.
Ephesians 2:4-5

“It is the Spirit who gives life; the flesh is of no avail. The words that I have spoken to you are spirit and life. But there are some of you who do not believe.” (For Jesus knew from the beginning who those were who did not believe, and who it was who would betray him.) And he said, “This is why I told you that no one can come to me [i.e. believe in me] unless it is granted him by the Father.”
John 6:63-65

You have been born anew, not of perishable seed but but of imperishable, through the living and abiding word of God..."�
1 Peter 1:23-25

Everyone who believes that Jesus is the Christ has been born of God.
1 John 5:1

Faith in the living God and his Son Jesus Christ is always the result of the new birth, and can never exist except in the regenerate. Whoever has faith is a saved man.
Charles Spurgeon from the sermon “Faith and Regeneration”

If salvation is the implantation of a new, infinite life in the soul, it must be a work of God. Self-caused effects can never rise above the character or qualities of their cause. "Flesh gives birth to flesh but the Spirit gives birth to Spirit," Jesus told Nicodemus. This saving grace cannot be caused by the creature, it can only come from God.
John Hannah from To God be the Glory (pg. 34-5)

The inward offer is a kind of spiritual enlightenment, whereby the promises are presented to the hearts of men, as it were, by an inward word.
William Ames