God is invisible. That fact creates speculation and misinterpretation.
People who don’t know better think that God is invisible because He does not exist. They liken Him to an “imaginary friend,” who lives only in the thoughts and hopes of the deluded faithful.
Even those who say that they believe in God suspect, although they may not say so, that God is invisible because He is in some sense less “real” than the visible world around us. They reason that He is spirit, and that spiritual things exist as sort of shadows of the more tangible and solid physical world.
Both of these ideas are incorrect. The truth is simple.
God is invisible because of His mercy.
God knows that no one can see Him and live, (see Genesis 33:19) and so in His mercy, God prevents us from seeing Him. If we did see Him, we would die.
Even Moses, to whom God spoke as one would speak to a friend (see Exodus 33:11), was prevented from actually seeing Him. On Mount Horeb, Moses asked God to show him His glory (in Exodus 33:18). God then declared to Moses His mercy, saying that He will be gracious to whom He would be gracious, and will show mercy to whom He will show mercy (in Exodus 33:19). Mercifully, He then immediately reminded Moses that no man could see Him and live. Instead, God offered to make all His goodness pass before Moses, without allowing Moses to see His face (in Exodus 33:20-23).
The next day, the Lord passed before Moses and proclaimed Himself, “The LORD, the LORD, a God merciful and gracious, slow to anger, and abounding in steadfast love and faithfulness, keeping steadfast love for thousands, forgiving iniquity and transgression and sin, but who will by no means clear the guilty…” (-Exodus 34:6-7, ESV)
We are reminded of the mercy of the invisible God in Colossians 1:14-15, when we are told of Christ,
…in whom we have redemption, the forgiveness of sins. He is the image of the invisible God,… (ESV)
In Christ, in Whom are the redemption of God and the forgiveness of God, we “see” the image of the invisible God. The glory of God that Moses beheld, we can see in Christ. He is the perfect likeness of the merciful God who makes Himself invisible in His mercy. In Christ, we see the the God who is merciful and gracious. In Christ, we see the God who is slow to anger. In Christ, we see the God who forgives iniquity, transgression, and sin without clearing the guilty. In Christ, we see the God who abounds in steadfast love (grace) and faithfulness (truth).
As John says,
And the Word became flesh and dwelt among us, and we have seen his glory, glory as of the only Son from the Father, full of grace and truth. And from his fullness we have all received, grace upon grace. For the law was given through Moses; grace and truth came through Jesus Christ.
No one has ever seen God; the only God, who is at the Father’s side, he has made him known. (-John 1:14, 16-18, ESV)
Because God is merciful, we cannot see Him. In His mercy, He has made Himself known to you, however, in Christ.
What is more, by receiving Him and the mercy of God, you can be given even more than a glimpse at the invisible God.
… to all who did receive him, who believed in his name, he gave the right to become children of God… (- John 1:12, ESV)
If you have received Him and believed in His name, you have seen the glory of God. You are now the child of God.
Declare the mercy of Christ, the image of God, Whose glory you, like Moses, have seen by the mercy of God.