From Craig Fisher:

Mal 3:6 “For I am the LORD, I do not change; Therefore you are not consumed, O sons of Jacob.

God is making a point: “I do not change, therefore you are not consumed.” Suppose God is saying: “I do not gain any new knowledge, therefore you are not consumed.”  Does this even make sense? How about “My essence does not change, therefore you are not consumed”? Again, this is nonsensical. We would be better to look towards the context of the text to understand its meaning.

Mal 3:1 “Behold, I send My messenger, And he will prepare the way before Me. And the Lord, whom you seek, Will suddenly come to His temple, Even the Messenger of the covenant, In whom you delight. Behold, He is coming,” Says the LORD of hosts.
Mal 3:2 “But who can endure the day of His coming? And who can stand when He appears? For He is like a refiner’s fire And like launderers’ soap.
Mal 3:3 He will sit as a refiner and a purifier of silver; He will purify the sons of Levi, And purge them as gold and silver, That they may offer to the LORD An offering in righteousness.
Mal 3:4 “Then the offering of Judah and Jerusalem Will be pleasant to the LORD, As in the days of old, As in former years.
Mal 3:5 And I will come near you for judgment; I will be a swift witness Against sorcerers, Against adulterers, Against perjurers, Against those who exploit wage earners and widows and orphans, And against those who turn away an alien— Because they do not fear Me,” Says the LORD of hosts.
Mal 3:6 “For I am the LORD, I do not change; Therefore you are not consumed, O sons of Jacob.
Mal 3:7 Yet from the days of your fathers You have gone away from My ordinances And have not kept them. Return to Me, and I will return to you,” Says the LORD of hosts. “But you said, ‘In what way shall we return?’

Through the context, one sees that the messenger of the Lord is coming. His mission is to purify the priests, the sons of Levi, in order that the offerings made by Israel may be acceptable to the Lord.  Also, the Lord is calling for a return to righteousness. He will exclude sorcerers, adulterers, perjurers, greedy business owners, and uncharitable people.  He punctuates these sins by saying “I do not change” meaning God still considers sin to be sin. He encourages Israel to drop their sins and return on to the Lord.  Those people who believe they are the chosen ones of God but can continue in their sins are deluded. God still punishes sinners, he does not change.

God is not changing his morality. There is no reference to the nature of God or to his knowledge. The threat of being consumed, the result clause of the syllogism “I do not change, therefore you are not consumed” would make no sense if God was referring to his nature or his knowledge. In fact if God is referring to his knowledge, he knows all future events. What is the purpose of his warning? The future would be fixed and God would know if Israel sinned or not. He would not have to warn them and offer a reward if they obeyed. The contingency of the warning is claim that God will change his mind about destroying Israel if they change their ways.

For original post, click here.