The word that meaning of 3:16 turns upon is "believes"
[Jhn 3:16 KJV] 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.
Belief is given as a fruit of the Spirit to those born-again. Only in that manner can someone truly believe (faith). So, 3:16
is referring to those who have become born-again, but not to everyone - it is not open-ended in that regard.
[Gal 5:22 KJV] 22 But the fruit of the Spirit is love, joy, peace, longsuffering, gentleness, goodness, faith,