One of the most important passages on holiness is the revelation Isaiah had of the glorified Messiah.

Isaiah 6:1-5.
I saw the Lord sitting on a throne, high and lifted up, and the train of His robe filled the Temple. Above it stood seraphim... And one cried to another and said, "Holy, holy, holy is the Lord of Hosts; the whole earth is full of His glory." And the posts of the door were shaken by the voice of him who cried out and the house was filled with smoke. So I said, "Woe is me for I am undone. Because 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."
Let us fix our eyes on Yeshua and desire to be holy like Him. There are seven attributes of holiness.

1. High and Lifted Up
There was something lofty and high about this vision of holiness. It is living on a higher plane. It makes me think about a person riding in a helicopter who is far above the traffic jams of the morning rush hour. Isaiah realized that the person he saw in this vision had something more than he had. He thought to himself, "I want to be close to Him. I want to be with Him. I want to be like Him. I want to be holy."

2. Shining in Light
A being filled with divine presence shines with light. This is called the glory of God. To be holy is to be filled with glory. Holiness is glorious. The whole earth will one day be filled with the glory of God through the children of God. As we become holy, we are also filled with light.

3. Full of Power
Holiness is the opposite of worldliness. To be holy we have to say "no" to the world, the flesh, and the devil. But holiness is more than just a list of "don'ts." After all, holiness existed before worldliness. To be holy is to come into the power of God. It is His ability. In this passage, His very presence shakes the whole building.

4. Splendid in Beauty
This holy and glorious figure is extremely attractive. Holiness is beautiful. The greatest pleasure of the world to come will be simply to gaze upon the beauty of the Lord (Psalm 27:4). This world is also filled with beautiful things. We are drawn to the world by the lust of our eyes. However, the beauty of the Lord in holiness is more beautiful and more attractive than the things of this world. We have something better to look at. We can worship the Lord in the beauty of His holiness. (Psalm 96:9).

5. Spiritually Clean
When one is holy, he is free from guilt and shame. He is not dirty on the inside. Isaiah, who was probably the most clean person living on the earth in his generation, immediately felt unclean when he looked at this perfectly clean being. He felt unclean and asked to be cleansed. To feel dirty on the inside is a terrible feeling. Just to be free from that sense of uncleanness, to be clean in our conscience, is already worth more than any of the pleasures and lusts of this world. We are cleansed by the blood of Yeshua and by the fire of the Holy Spirit.

6. Morally Pure
Holiness is the highest level of purity. It is the highest level of morality. One aspect of that is to have pure motives. Many of us have decently good motives, but they are not really pure. Even when people do good things, there are certain selfish motives behind it. To be really pure would be to have your thoughts and motives openly known for everyone to see. We can only have truly pure motives when we yield to the leading of the Holy Spirit within us, and act by His motives.

7. Wholly Perfect
To be holy is to be perfect. Our father in heaven is perfect, and Yeshua calls us to be perfect like Him (Matthew 5:48). After we are saved, we enter into a process of being made perfect by the Holy Spirit. That is the process of sanctification. Through the promises of God, we cleanse ourselves both in spirit and body to become perfect in holiness (2 Corinthians 7:1). Thought we are not perfect yet, we press on toward the goal of becoming perfectly holy (Philippians 3:12).