I am the Lord, and I do not change. And so you...are not yet completely lost. Mal. 3:6, T.E.V.
Our usual picture of the religious legalist is of one with permanent worry marks on his brow, collecting endless lists of good things to do and bad things to avoid doing. His religious vocabulary is heavily spiced with words such as "duty," "obedience," and "perfection." And he dreads nothing more than that he might do something that would incur the disfavor of a hypersensitive God. To speak of him as a rebel against God would be, in his eyes, grounds for a libel suit.
But consider again the root motivation of the legalist. His most intense desire is that his diligent efforts at goodness might persuade God to change toward him and to grant favors of grace or kindness He might otherwise not offer. The legalist assumes that he knows exactly what he most needs and wants. Indeed, he knows better than God does, and were he not coaxing those gifts from God, God would not likely grant them.
As such, the legalist is saying that he is better off in his own hands than is the hands of God. He is convinced that he can take better care of himself than God can, were he given the controlling vote. His life is a protest that the gifts of forgiveness and acceptance are held in the hands of a niggardly God who is not inclined to part with them except when coaxed or obligated. The legalist, then, believes himself to be higher, wiser, and more loving than God. And surely that is the ultimate rebellion!
Any time I approach God with a desire to change His attitudes or actions toward me, I am reverting to the posture of a legalist. When God said, "I am the Lord, and I do not change," He was not making a petulant remark or announcing a closed mind. Our Father does not change toward us, because there is nothing in His perfectly loving and wise attitude toward us that needs changing.
God said, "I am the Lord, and I do not change. And so you...are not yet completely lost." We dwell in grace, every one of us. Though each of us has sinned, we have each been granted life--and a lifesaving opportunity to change our minds. We have not died, not because we have begged for our lives but because our unchanging God is gracious by nature.