John 3:16. Read it.
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.
— John 3:16
"Whosoever believeth in him."
Who is "him"? The answer seems obvious. The nearest noun is "Son." Most of the time, that settles it. But if you stop and look at the sentence, the whole thing is about God. God loved. God gave. The Son is what God gave. And the purpose — "that whosoever believeth in him" — completes the thought about God.
On its own, the grammar is not as clear as we pretend.
Now read John 5:24.
He that heareth my word, and believeth on him that sent me, hath everlasting life, and shall not come into condemnation; but is passed from death unto life.
— John 5:24
No ambiguity here. Jesus says: "Believeth on him that sent me." The one believed on is the Father. That is plain.
So here is the question.
If scripture does not contradict itself, and John 5:24 says saving faith lands on the Father, then what does John 3:16 actually mean? Does "him" refer to the Son or the Father?
Read John 3:16 again.
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.
— John 3:16
God loved. God gave. The whole verse is about what God did. The Son is the gift. "Him" refers back to God — the Giver of the sentence, not the gift he gave. The nearest noun theory says "him" is the Son. But the context says the verse is about God.
The words line up. The tension was never in the text. It was in what we were taught to expect.
Now comes the real question.
And this is the condemnation, that light is come into the world, and men loved darkness rather than light, because their deeds were evil.
— John 3:19
Light has come into the world. The truth is here in front of you. The Father is the Giver. The Son is the sent one. Faith rests in the Giver alone.
Will you accept the light or remain in the dark?
If you need one more witness, Jesus makes it explicit in his prayer.
And this is life eternal, that they might know thee the only true God, and Jesus Christ, whom thou hast sent.
— John 17:3
Eternal life is knowing the Father — the only true God — and the Son he sent. The Giver is the source; the Son is the sent one. Jesus himself keeps them distinct.
There's a difference between trusting the Giver and trusting the gift. John 3:16 says God gave his Son so that we could believe in God. The Son is the gift. Saving faith, Jesus himself says, lands on the one who sent him.
Faith rests in the Giver alone. The Son is the one who shows us where to look.