Leviticus 10:1-3 — And Nadab and Abihu, the sons of Aaron, took either of them his censer, and put fire therein, and put incense thereon, and offered strange fire before the Lord, which he commanded them not. And there went out fire from the Lord, and devoured them, and they died before the Lord. Then Moses said unto Aaron, This is it that the Lord spake, saying, I will be sanctified in them that come nigh me, and before all the people I will be glorified. And Aaron held his peace.

Yesterday I wrote that it seems more and more difficult to have people recognize the reality of sin. Today I want to talk about what I believe to be the root cause of that moral decline.
Put simply, most people — even many church-going Christians — have forgotten that God is holy. I don’t know that there is any point addressing the rest of this piece to non-Christians. If you’re reading this I can only beg you to surrender your life to Jesus. Until you do you are irretrievably alienated from a Holy God.
But we Christians … we need to remember that God is holy.
Remembering who God is would surely be the most effective preventive to sin. Failing to do so is, as Nadab and Abihu did, will prove fatal. It is not clear to me that their intentions were anything but pure — but they were acting not in response to God’s direction, but in response to the prompting of their own wills. God’s reaction is fierce, and immediate. He demands precise obedience — all the more so from those honored by the call to His service. Charles Erdman, in his study of Leviticus makes the point, “The words ‘them that come nigh me,’ were, in the first instance, addressed to the priests, but the message is for all who approach God as worshippers.”
If we take seriously the idea that God is Holy we are forced to recognize that the moral distance between us and Him is as great as the distance between us and His infinite reach. It should make us see sin in its proper perspective. R. C. Sproul sets us right in his book “The Holiness of God”:

Sin is cosmic treason. Sin is treason against a perfectly pure Sovereign. It is an act of supreme ingratitude toward the One to whom we owe everything, to the One who has given us life itself. Have you ever considered the deeper implications of the slightest sin, of the most minute peccadillo? What are we saying to our Creator when we disobey Him at the slightest point? We are saying no to the righteousness of God. We are saying, “God, Your law is not good. My judgement is better than Yours. Your authority does not apply to me. I am above and beyond Your jurisdiction. I have the right to do what I want to do, not what You command me to do.

We have become accustomed to think of God more as a benevolent friend than a Holy Lord. We have slipped into the habit of seeing even small sins as social discourtesies to that good friend instead of treason against that great Lord. It is one of Satan’s best strategies, brilliantly described by C. S. Lewis in the Screwtape Letters, “It does not matter how small the sins are provided that their cumulative effect is to edge the man away from the Light and out into the Nothing.“