[John 3:3, 5 KJV] 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. ... 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.
Only Israel could be born again. Israel was born of God as his firstborn son. Christ was saying they had to be born again by the spirit.
[Exo 4:22 KJV] 22 And thou shalt say unto Pharaoh, Thus saith the LORD, Israel [is] my son, [even] my firstborn:
The verses above in John 3 speak of the Kingdom of God.
The kingdom is found in the prophets:
[Isa 9:7 KJV] 7 Of the increase of [his] government and peace [there shall be] no end, upon the throne of David, and upon his kingdom, to order it, and to establish it with judgment and with justice from henceforth even for ever. The zeal of the LORD of hosts will perform this.
[Dan 7:18 KJV] 18 But the saints of the most High shall take the kingdom, and possess the kingdom for ever, even for ever and ever.
Jesus was saying the prophetic kingdom was at hand:
[Mat 4:17, 23 KJV] 17 From that time Jesus began to preach, and to say, Repent: for the kingdom of heaven is at hand. ... 23 And Jesus went about all Galilee, teaching in their synagogues, and preaching the gospel of the kingdom, and healing all manner of sickness and all manner of disease among the people.
The kingdom is described in the prophets
Israel will be restored:
[Deu 30:3 KJV] 3 That then the LORD thy God will turn thy captivity, and have compassion upon thee, and will return and gather thee from all the nations, whither the LORD thy God hath scattered thee.
[Deu 30:5 KJV] 5 And the LORD thy God will bring thee into the land which thy fathers possessed, and thou shalt possess it; and he will do thee good, and multiply thee above thy fathers.
[Isa 11:9 KJV] 9 They shall not hurt nor destroy in all my holy mountain: for the earth shall be full of the knowledge of the LORD, as the waters cover the sea.
[Isa 56:7 KJV] 7 Even them will I bring to my holy mountain, and make them joyful in my house of prayer: their burnt offerings and their sacrifices [shall be] accepted upon mine altar; for mine house shall be called an house of prayer for all people.
[Isa 65:25 KJV] 25 The wolf and the lamb shall feed together, and the lion shall eat straw like the bullock: and dust [shall be] the serpent's meat. They shall not hurt nor destroy in all my holy mountain, saith the LORD.
The Lord will make a new covenant with Israel:
[Jer 31:31, 33 KJV] 31 Behold, the days come, saith the LORD, that I will make a new covenant with the house of Israel, and with the house of Judah: ... 33 But this [shall be] the covenant that I will make with the house of Israel; After those days, saith the LORD, I will put my law in their inward parts, and write it in their hearts; and will be their God, and they shall be my people.
The new covenant will be the water and the spirit that Jesus said was needed to enter the kingdom on earth. To see the kingdom in John 3:3 entails seeing the kingdom by being in it:
[Eze 36:24-27 KJV] 24 For I will take you from among the heathen, and gather you out of all countries, and will bring you into your own land. 25 Then will I sprinkle clean water upon you, and ye shall be clean: from all your filthiness, and from all your idols, will I cleanse you. 26 A new heart also will I give you, and a new spirit will I put within you: and I will take away the stony heart out of your flesh, and I will give you an heart of flesh. 27 And I will put my spirit within you, and cause you to walk in my statutes, and ye shall keep my judgments, and do [them]
Only Israel could be born again. Israel was born of God as his firstborn son. Christ was saying they had to be born again by the spirit.
[Exo 4:22 KJV] 22 And thou shalt say unto Pharaoh, Thus saith the LORD, Israel [is] my son, [even] my firstborn:
The verses above in John 3 speak of the Kingdom of God.
The kingdom is found in the prophets:
[Isa 9:7 KJV] 7 Of the increase of [his] government and peace [there shall be] no end, upon the throne of David, and upon his kingdom, to order it, and to establish it with judgment and with justice from henceforth even for ever. The zeal of the LORD of hosts will perform this.
[Dan 7:18 KJV] 18 But the saints of the most High shall take the kingdom, and possess the kingdom for ever, even for ever and ever.
Jesus was saying the prophetic kingdom was at hand:
[Mat 4:17, 23 KJV] 17 From that time Jesus began to preach, and to say, Repent: for the kingdom of heaven is at hand. ... 23 And Jesus went about all Galilee, teaching in their synagogues, and preaching the gospel of the kingdom, and healing all manner of sickness and all manner of disease among the people.
The kingdom is described in the prophets
Israel will be restored:
[Deu 30:3 KJV] 3 That then the LORD thy God will turn thy captivity, and have compassion upon thee, and will return and gather thee from all the nations, whither the LORD thy God hath scattered thee.
[Deu 30:5 KJV] 5 And the LORD thy God will bring thee into the land which thy fathers possessed, and thou shalt possess it; and he will do thee good, and multiply thee above thy fathers.
[Isa 11:9 KJV] 9 They shall not hurt nor destroy in all my holy mountain: for the earth shall be full of the knowledge of the LORD, as the waters cover the sea.
[Isa 56:7 KJV] 7 Even them will I bring to my holy mountain, and make them joyful in my house of prayer: their burnt offerings and their sacrifices [shall be] accepted upon mine altar; for mine house shall be called an house of prayer for all people.
[Isa 65:25 KJV] 25 The wolf and the lamb shall feed together, and the lion shall eat straw like the bullock: and dust [shall be] the serpent's meat. They shall not hurt nor destroy in all my holy mountain, saith the LORD.
The Lord will make a new covenant with Israel:
[Jer 31:31, 33 KJV] 31 Behold, the days come, saith the LORD, that I will make a new covenant with the house of Israel, and with the house of Judah: ... 33 But this [shall be] the covenant that I will make with the house of Israel; After those days, saith the LORD, I will put my law in their inward parts, and write it in their hearts; and will be their God, and they shall be my people.
The new covenant will be the water and the spirit that Jesus said was needed to enter the kingdom on earth. To see the kingdom in John 3:3 entails seeing the kingdom by being in it:
[Eze 36:24-27 KJV] 24 For I will take you from among the heathen, and gather you out of all countries, and will bring you into your own land. 25 Then will I sprinkle clean water upon you, and ye shall be clean: from all your filthiness, and from all your idols, will I cleanse you. 26 A new heart also will I give you, and a new spirit will I put within you: and I will take away the stony heart out of your flesh, and I will give you an heart of flesh. 27 And I will put my spirit within you, and cause you to walk in my statutes, and ye shall keep my judgments, and do [them]