For I, the Lord, do not change;
therefore you, O sons of Israel
are not consumed.
If you read any book or article on the attributes of God you will find Him described as immutable, and usually they will go on to talk about the unchangableness of His nature and character. However, the word has a deeper meaning than just being unchangeable, it means that in being unchangeable, one is not capable or susceptible to change. When you grasp that concept, then considering God's immutability takes on a whole new light.
This means that it is impossible for God to change, impossible for God to be other than He is. There is never the potentiality of His changing in any way, in any measure (James 1:17). His mercy will always be His mercy, His wrath will always be His wrath, His grace will always be His grace, His power will always be His power. There will never be any diminishment in who He is, because there cannot be any diminishment in who He is; and He cannot be more than He is, He cannot be improved upon, because He is already perfect. When God tells us that from age to age He is the same, we must understand that from eternity past to eternity future it is impossible for Him to not be the same. Change in His person, purpose, thoughts, and very nature literally cannot take place. He is the rock that does not erode, the fortress and refuge that is always secure, the love that will never fail. Therefore, His yes is always yes, and His no is always no; and, therefore, His word never changes or shifts, even ever so slightly. He is the model of absolute consistency. He is the same God in the Old Testament as He is in the New Testament.
To me, this is very comforting. It gives me a deeper trust and confidence in not only Him, but in His word. It is this unchangeableness that is behind the Scriptures. It is why the Word of God cannot and will not change to meet the demands of the shifting moral climate of each era of the human race. All of this means that He is absolutely dependable, reliable, and trustworthy. It means there will be a consistency in His dealings with me, a consistency in His love for me, and a consistency in His patience with me no matter the twists and turns that I encounter in this life. It is the anchor in my relationship with Him.
So, my friends, let us consider the absolute unchangeableness of this God who has called us and claimed us, who has loved us and blessed us, and who leads us in the paths of righteousness. Let us draw near and draw great comfort in knowing it is impossible for Him to change.