John expands on John 1:18 in John 6:46, in that no man has seen God the Father at anytime. The OT is full of Theophanies, where people saw the Son of God “face to face”.
John 6:46
No one has seen the Father except the one who is from God; only he has seen the Father.
Some Theophanies,
Genesis 32:30
So Jacob called the place Peniel, saying, “It is because I saw God face to face, and yet my life was spared.”
Exodus 33:11
The LORD would speak to Moses face to face, as a man speaks with his friend. Then Moses would return to the camp, but his young aide Joshua son of Nun did not leave the tent.
Numbers 12:8
With him I speak face to face, clearly and not in riddles; he sees the form of the LORD. Why then were you not afraid to speak against my servant Moses?"
Numbers 14:14
And they will tell the inhabitants of this land about it. They have already heard that you, O LORD, are with these people and that you, O LORD, have been seen face to face, that your cloud stays over them, and that you go before them in a pillar of cloud by day and a pillar of fire by night.
Deuteronomy 5:4
The LORD spoke to you face to face out of the fire on the mountain.
Deuteronomy 34:10
Since then, no prophet has risen in Israel like Moses, whom the LORD knew face to face,
Judges 6:22
When Gideon realized that it was the angel of the LORD, he exclaimed, “Ah, Sovereign LORD! I have seen the angel of the LORD face to face!”
google.com/search?hl=en&sa=X&oi=spell&resnum=0&ct=result&cd=1&q=Old+Testament+Theophanies&spell=1
The reason the Father can not be approached by natural man is that he lives in unapproachable light.
1 Timothy 6:16
who alone is immortal and who lives in unapproachable light, whom no one has seen or can see. To him be honor and might forever. Amen.
It is simply God the Father, whom natural man can not approach or see directly. The Second person of the trinity made himself known via theophanies in the old testament.
