Sometimes God seems to overreact. In Leviticus 10 we read about people who dropped dead simply because they didn't worship correctly. Priests were threatened with death if they didn't stay well-groomed or if they wandered away from the tabernacle. To modern readers who like to dress casual and live free, all of this sounds a bit stifling.
But the aim of this instruction is not to tell us how to dress for church. It tells us about God. It reminds us that God is holy, and He is not to be trifled with. God is not a buddy who just wants us to feel comfortable around Him.
The Scriptures do not merely educate us in morality. God didn't give us the Bible to teach us how to be good little boys and girls. Instead, Scripture demands that we live respectfully and worshipfully in the awesome presence of the holy God. Without God's holiness, our faith loses its meaning. British theologian P. T. Forsyth (1848-1921) wrote, "Sin is but the defiance of God's holiness, grace is but its action upon sin, the cross is but its victory, and faith is but its worship."
Angels in the presence of God call to one another, "Holy, holy, holy, Lord God Almighty!" (Rev. 4:8). If we are believers in Christ, we can join them in that chant. — Haddon W. Robinson
The holiness of God reveals
Our insufficiency;
But when His Spirit fills our hearts,
His work in us we'll see. --Sper
To refrain from sin doesn't make us holy, but holiness makes us refrain from sin.