I think I would have to begin with the words of John as my starting point: “No one has seen God at any time. The only begotten Son, who is in the bosom of the Father, He has declared Him” (John 1:18, NKJ). This is a propositional statement which is the clearest of all, so I would look at the texts you have pointed out in the light of what Scripture has said in John 1. We can begin with Genesis chapter 3:
8 And they heard the sound of the LORD God walking in the garden in the cool of the day, and Adam and his wife hid themselves from the presence of the LORD God among the trees of the garden. 9 Then the LORD God called to Adam and said to him, “Where are you?” 10 So he said, “I heard Your voice in the garden, and I was afraid because I was naked; and I hid myself.”
[Actually, we are not told that Adam and Eve “saw” God, but only that they “heard the sound of the Lord.”]
Now to Exodus 33:
17 So the LORD said to Moses, “I will also do this thing that you have spoken; for you have found grace in My sight, and I know you by name.” 18 And he said, “Please, show me Your glory.” 19 Then He said, “I will make all My goodness pass before you, and I will proclaim the name of the LORD before you. I will be gracious to whom I will be gracious, and I will have compassion on whom I will have compassion.” 20 But He said, “You cannot see My face; for no man shall see Me, and live.” 21 And the LORD said, “Here is a place by Me, and you shall stand on the rock. 22 “So it shall be, while My glory passes by, that I will put you in the cleft of the rock, and will cover you with My hand while I pass by. 23 “Then I will take away My hand, and you shall see My back; but My face shall not be seen.” (Exodus 33:17-23)
[Here, it is clear that Moses saw something of God, but He did not see Him fully, as God Himself indicates. God said that if anyone saw His face, he would die (v. 20)]
9 Then Moses went up, also Aaron, Nadab, and Abihu, and seventy of the elders of Israel, 10 and they saw the God of Israel. And there was under His feet as it were a paved work of sapphire stone, and it was like the very heavens in its clarity. 11 But on the nobles of the children of Israel He did not lay His hand. So they saw God, and they ate and drank (Exodus 24:9-11).
[Here, Moses and the 70 elders of Israel “see” the God of Israel in some way, shape or form, but note, “there appeared to be…” in verse 10. Once again, there was no full, face to face “seeing”]
7 Moses took his tent and pitched it outside the camp, far from the camp, and called it the tabernacle of meeting. And it came to pass that everyone who sought the LORD went out to the tabernacle of meeting which was outside the camp. 8 So it was, whenever Moses went out to the tabernacle, that all the people rose, and each man stood at his tent door and watched Moses until he had gone into the tabernacle. 9 And it came to pass, when Moses entered the tabernacle, that the pillar of cloud descended and stood at the door of the tabernacle, and the Lord talked with Moses. 10 All the people saw the pillar of cloud standing at the tabernacle door, and all the people rose and worshiped, each man in his tent door. 11 So the LORD spoke to Moses face to face, as a man speaks to his friend. And he would return to the camp, but his servant Joshua the son of Nun, a young man, did not depart from the tabernacle (Exodus 33:7-11).
[Note that in this text it does not say that Moses “saw” God face to face, but that he spoke to Him “face to face, as one speaks to his friend” (v. 11). I take this to be some form of anthropomorphism, speaking of an intimate conversation with God in human terms, but not indicating the seeing of God’s face, which, in the following chapters, God forbids Moses to do. Incidentally, the figure of speech used for God being angry is, literally, something like: God’s nose burned.]
To see Christ is to see the Father, but is this to see the Father “fully”? I think not. In His incarnation, our Lord’s full glory was “veiled,” with sneak previews like the transfiguration. But when John saw our Lord glorified in Revelation 1, he fell before Him as a dead man (by the way, was this not in a vision? Rev. 1:9-17). It is this John who has said that he “saw the Lord” “with his own eyes” (along with the others) in 1 John 1:1-2. And yet in the same book, he writes,
“Beloved, now we are children of God; and it has not yet been revealed what we shall be, but we know that when He is revealed, we shall be like Him, for we shall see Him as He is” (1 John 3:2, NKJV).
It seems to me that there are at least two elements involved in man’s not being able to see God. The first is that God is spirit, and can’t be seen apart from divine enablement (this was true even of the angels (2 Kings 6:17). Thus, what men saw of God must have been a kind of partial manifestation of God. When our Lord came to the earth, men did see God manifested in human flesh, but still not in the full radiance of His glory, as John seems to indicate in 1 John 3:2.
Certainly we would have to say that at this moment in time, when Christ is not present among us in body God is invisible, and thus we come to know Him in terms of His attributes through His Word.
Second, man is not able to look upon a holy God in his present sinful condition. From 1 John 3:2 it would seem as though there will be a time when we shall see Him “as He is,” when we behold Him in glory. This may also be related to Paul’s words in 2 Corinthians chapter 12, when he was “caught up into the third heaven” and saw glorious things, and yet was not permitted to speak of them. These were “heavenly things” which earthly folks are not able to “see” at present, while on this earth and in our mortal bodies.