John 3:14 And as Moses lifted up the serpent in the desert, so must the Son of man be lifted up: (notice the punctuation)
John 3:15 That whosoever believeth in him, may not perish; but MAY have life everlasting.
John 3:16 For God so loved the world, as to give his only begotten Son; that whosoever believeth in him, MAY not perish, but MAY have life everlasting.
Where did it say that those who, when bitten by a snake, looked to the serpent Moses lifted up in the desert to be healed they were also assured of never being bitten again and therefore again in need of looking to the serpent Moses raised? It says that when bitten they had to look at the serpent Moses had raised up. Not a thing is said about their then being assured of never being bitten again.
MAY have is NOT the same as WILL have. Sorry, but John 3:16 in no way says anything about "once saved always saved" unless you prefer to twist it to suit your personal preconceptions.
This is exactly what I'm talking about when I wrote "immature." You are completely missing the spiritual context of the scripture.
So, what you think John 3:16 actually means is those who "believe" in God's Son, may also perish, even if you believe in his son.
This is why it's so hard for a prideful man to hear God. If you think you control your salvation based on whether you "sin" or not
after you've accepted Christ, you're still drinking milk!
John 3:16 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.
Now, I can show you many versions of this scripture that does not use "MAY." What Bible are you quoting from? Furthermore, your misinterpreting "may."
John 3:16 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.