In the Greek Interlinear I find the word spirit is in lower-case letters at John 3:5. KJV took the liberty to use a capital "S".
So, when Jesus was baptized - Luke 3:22 - God's spirit was in bodily shape as a 'bird' aka a 'dove'. see also Mark 1:10.
God's spirit is described as a 'gift ' (Not a person) at Acts 2:38,41, spiritual blessings - Ephesians 1:3
So, when God sends forth His powerful spirit (Psalm 104:30) things happen.
Of course, pretty much nothing was capitalized. It didn’t have commas or periods. As noted in other scriptures… it is a person.
Also, it's good to remember John 3:13 because No one who died before Jesus (such as John the Baptist) were offered Heaven.
Those born again are like the people found at Luke 22:28-30; Daniel 7:18.
That isn’t quite true… There was a place called Paradise or Abrahams Bosom that held the righteous until Heaven was opened to them (at the resurrection). Hebrews addresses it as:
Hebrews 11:13