This is a play on words using Notarikon.
Notarikon is first demonstrated in the gospels. Without getting into a discussion about which book came first, it can be demonstrated that John was proficient in the use of it.
John uses the first three words of Ge 1:1 to derive his theology of Jo 1:1-4.
The word 'bara' הרא is translated 'created', but because God spoke when he created , it is also interpreted as 'the word which creataed'.
The word 'bereshith' בראשית, translated 'in the beginning' contains 'bara' ברא so he says: In the beginning was the word.
Bara is next to God אלהים , so he says: and the word was with God.
Bara ברא is broken into 'bar-a' בר א which is 'the son who spoke and created the heavens and the earth. John says: the word was God [the creator]
Elohim has three puns:
אלחים 'alo khoom' - not אל dark חום, the light. John says He is the light.
לחם 'lechem' - bread לחם. John says he is the bread.
אלחיים God's אל life הים. John says he is the life.
(see https://sensusplenior.net/wiki/Ge_1:1 for a complete breakdown)
John further demonstartes his competency in notarikon in 1 Jo 5:7,8
1Jo 5:6 ¶ This is he that came by water and blood, [even] Jesus Christ; not by water only, but by water and blood. And it is the Spirit that beareth witness, because the Spirit is truth.
1Jo 5:8 And there are three that bear witness in earth, the Spirit, and the water, and the blood: and these three agree in one.
Heaven שמים is the Father מ the Word ם and the Spirit ש and has gematria =3.
Earth ארץ is the Spirit (a secondary metaphor of the aleph: the Spirit hovered over the face of the water when God spoke and created the heavens and the earth.), the water ר, and the blood ץ. Earth ארץ has gematria = 3.
John was proficient in notarikon. It is likely that Jesus taught it in the temple when he was 12. The teachers had 18 years to pervert his teaching, evidenced with the perversion of his teaching with the confrontation concerning the woman with seven husbands. Jesus then called them liars rather than misinformed teachers, because they had perverted his teaching. Eliezer was cast out of Judaism as a heretic, even though his teaching is still one of the most revered. Again it is likely, that he became a Christian. This paragraph is speculation based on circumstantial evidence presented only to show the plausibility of how he derived it from the teaching of the apostles.
Waters is מים . This is creation י in the Father מ and the Son ם.
The shin represents the Spirit which gives life ש
Put the together and you get heaven שמים .
One must be born of the water מים and the Spirit ש to be in 'heaven' שמים.
With this saying, and the others above, it might be argued that John is teaching notarikon.
The Greek church abandoned the use of Notarikon even before they knew it, eliminating the Hebrew text in favor of the Septuagint.
Obviously here, the Hebrew play on words is being expressed in Greek.