He quickens after one believes and He demands our believing on the Son! Then He gives the gift of salvation after one has placed their in His dear Son. Ephesians 2:8 &9 "For by Grace are you saved through Faith and not of ourselves it (salvation) is the gift of God, lest any man should boast."
We are to follow God's commandments and one of those commands for salvation is to believe. But let's look again at Eph. 2:8, for by Grace ye saved through Faith. Now which word is the verb? "Saved" thus it sets the subject or syntax of the verse, so that when one gets to the prepositional phrase it is the gift, the Pronoun it relates back to the verb, which is "saved or salvation." So therefore Salvation is the gift of God. How do we obtain that gift, by Grace, but what means through Faith, so we must believe in order to be saved. Grace brings salvation and God requires everyone to Believe on the Son in order to be saved. So that salvation makes us reborn, that we become Spiritually born, why must we be spiritually born, because we are spiritually dead in trespasses and sins and devoid of spiritual things.
And this is seen for the command in John 3:
2 "he same came to Jesus by night, and said unto him, Rabbi, we know that thou art a teacher come from God: for no man can do these miracles that thou doest, except God be with him.
3 Jesus answered and said unto him, Verily, verily, I say unto thee, Except a man be born again, 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?"
Notice verse 3 "except a man be born again" How does one gain the second birth, that is salvation and the second birth is also regeneration,
Now one more thing in John 3:
14 "And as Moses lifted up the serpent in the wilderness, even so must the Son of man be lifted up:
15 That whosoever believeth in him should not perish, but have eternal life.
16 For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life."
Christ was lifted up on the cross so that whosoever believeth in Him should not perish, How do they not perish? They gain eternal life and what life is eternal? Spiritual life, and the spiritual life is brought about by belief. Then going to Revelation 20:
14 "And death and hell were cast into the lake of fire. This is the second death.
15 And whosoever was not found written in the book of life was cast into the lake of fire."
Notice failure to believe causes one to suffer the second death. You think that is stretch, let's see this takes us right back to John 3:
36 "He that believeth on the Son hath everlasting life: and he that believeth not the Son shall not see life; but the wrath of God abideth on him."
Those who believe on the Son have everlasting Life, that would mean their names must be written in the book of life seen in Revelation 20 and what about those who believe not, they shall not see life, wow, right back to Revelation 20 death, that is those who died in their trespasses and sin don't see life they suffer the second death, that is eternally separated from God, why, Jesus said because they don't believe.
Now that begs the question, if God requires one to believe and scripture is very clear He does then why would He regenerate some before they are reborn by believing and not others when Jesus clearly states in John 12:32, He would Draw ελκυσω, Elkyo, now I have heard that this means to drag as a net, but according to George Ricker Berry's Greek Lexicon, this word only sometimes involves force, often not. In its use here it means to draw over, to persuade. Thus Jesus is saying He would persuade men to come to Him. How, faith cometh by hearing and hearing by the word of GOD.
Revelation 22:17
"And the Spirit and the bride say, Come. And let him that heareth say, Come. And let him that is athirst come. And whosoever will, let him take the water of life freely."
The Spirits message to all is come, the churches message to all is come, the invitation is to all to come and take the water of life freely, it is the gift of God, not of works and it is obeying God's command to believe and the Holy Spirits' persuasion to come.