Isaiah had a vision in which he saw the Seraphim praising God for his holiness.
In the year that King Uzziah died I saw the Lord sitting upon a throne, high and lifted up; and the train of his robe filled the temple. Above him stood the seraphim. Each had six wings: with two he covered his face, and with two he covered his feet, and with two he flew. And one called to another and said:
“Holy, holy, holy is the LORD of hosts;
the whole earth is full of his glory!”
Isaiah 6:1-3 ESV
John later saw the same thing.
And around the throne, on each side of the throne, are four living creatures, full of eyes in front and behind: the first living creature like a lion, the second living creature like an ox, the third living creature with the face of a man, and the fourth living creature like an eagle in flight. And the four living creatures, each of them with six wings, are full of eyes all around and within, and day and night they never cease to say,
“Holy, holy, holy, is the Lord God Almighty,
who was and is and is to come!”
Revelation 4:6-8 ESV
The seraphim were praising God’s holiness in 740 BC when Isaiah had his vision. They were doing it when John was taken to Heaven in about AD 90. As far as we know they are doing the same thing today. This suggests that holiness is God’s most important attribute.
Today we hear more about God’s love than about his holiness. Many ask, “If God loves us why doesn’t he just forgive everyone’s sins? Why do we have to put our faith in Christ?” If we only consider God’s love those are legitimate questions. We need to remember that God can’t express love in a way that contradicts his holiness. All sin must be paid for; either the sinner must be punished or the sin must be atoned for with a blood sacrifice.
Without the shedding of blood there is no forgiveness of sins.
Hebrews 9:22 ESV
The only blood that atones for human sin is that of Jesus Christ. His resurrection proves that God has accepted his sacrifice. Whoever puts his faith in Christ is made holy and fit to enter the presence of God; anyone who fails to do this must bear the punishment he deserves.
The holiness of God explains why Hell must be eternal. Anyone who sins against an infinitely holy God deserves eternal punishment.
When Isaiah saw God his first reaction was a consciousness of his own sinfulness.
And I said: “Woe is me! For I am lost; for I am a man of unclean lips, and I dwell in the midst of a people of unclean lips; for my eyes have seen the King, the LORD of hosts!”
Isaiah 6:5 ESV
Most people think they live good lives. They are generally aware of areas where they don’t fully measure up to what they know is right, but they don’t think their failures are of vital importance. That is because we are in a state of spiritual darkness where we don’t see things as God sees them. The light of God’s holiness enables us to see ourselves as we really are.
If we want to know God we need to begin by understanding his holiness. Until we see him as holy our understanding of his actions will be flawed.