Summary: Examining the bright distinction between Holy God and fallen mankind.
“Come now, let us reason together, says the LORD:
though your sins are like scarlet,
they shall be as white as snow;
though they are red like crimson,
they shall become like wool.
If you are willing and obedient,
you shall eat the good of the land;
but if you refuse and rebel,
you shall be eaten by the sword;
for the mouth of the LORD has spoken.”
We have acquired a new evangelical God. He no longer burns with the fire of judgement or shines with the blinding white light of unapproachable righteousness. His Son is not stained with the blood of the sacrifice, nor are His followers aware of any blood on their own hands that would put them in need of such a sacrifice. He is a kinder, gentler God, more in touch with the felt needs of the people. This God is fashionable; He matches the prevailing colour of newer sanctuaries. Colour Him mauve.
For most of history, God has not been popular. He has been more inclined to choose the weak things over the strong. Most people have thought His message foolish. He used to say that the fear of Him was the first step in finding Him. No wonder so few have followed Him. Of course, all that has changed since God has adopted mauve as His colour.
This is exciting news for ministers. They can finally put behind them the maligning they used to get from the world and preach a gospel everyone will be eager to hear—God really does like us; He accepts us just as we are and without demanding that we change! Those scary messages about sin and guilt and judgement and the cross were old-fashioned ways of telling people that God wants them to feel good about themselves. All that about judging sin and dying on the cross—that was God’s business, theological stuff He had to deal with so He could be nice. Now that it’s over, people don’t need to hear about all that uncomfortable stuff. All they need to know is that God likes them and has wonderful plans for their lives.
I trust you recognise the sarcasm. Though much of the teaching of the Old Covenant is rejected as overly harsh and far too demanding, it is nevertheless the Word of God. We dare not dismiss what has been written there as though it had no value for us today. What we do discover when we encounter God in the pages of the Word is a God defined by bold colours.
Contemporary religious ideals are presented in dull, drab greys and muted shades; however, the Bible portrays God in brilliant, bold, scintillating colours that cannot be toned down. Mankind’s sinful condition and the Lord’s holy perfection stand in distinct contrast to one another—the brilliance of His righteousness cannot be mixed or blended with the darkness of mankind’s sinful condition. Job asked the question, “Who can produce something pure from what is impure?” Then, he answered his own question: “No one” [JOB 14:4]! 
Failure to make a distinction between what is holy and what is unholy brought censure on the priests under the Old Covenant. God, speaking through Ezekiel charged, “[Judah’s] priests have done violence to my law and have profaned my holy things. They have made no distinction between the holy and the common, neither have they taught the difference between the unclean and the clean, and they have disregarded my Sabbaths, so that I am profaned among them” [EZEKIEL 22:26].
You will recall that there was to be a bold distinction between the holy and the common. Moses had given the instruction in the Law, “You are to distinguish between the holy and the common, and between the unclean and the clean, and you are to teach the people of Israel all the statutes that the LORD has spoken to them by Moses” [LEVITICUS 10:10, 11]. Even in the matter of food, those responsible to instruct the people were “to make a distinction between the unclean and the clean and between the living creature that may be eaten and the living creature that may not be eaten” [LEVITICUS 11:47]. Even down to the Millennial reign of the Lord Jesus, those appointed to holy office are responsible to discriminate, to distinguishing between holy and common. “[The priests] shall teach my people the difference between the holy and the common, and show them how to distinguish between the unclean and the clean” [EZEKIEL 44:23].
THINK! “Come, now, let us reason together, says the Lord.” Thus does God call His people to think; He challenges them to engage in vigorously defending their case. “Reason together” is a rather weak translation of the Hebrew. This is a judicial term used when one would argue his case in a court of law. It speaks of arguing or proving the case.  Perhaps it would be more accurate to translate this challenge, “Let us debate the case in court.”  In short, God challenges Israel, and consequently all who read this challenge, to think! Consider how to frame your disobedience to Him; think carefully in order to see if it is rational or reasonable.