The Lord speaks in Malachi 3:6
“For I am the LORD, I change not;” this statement is not in reference to rigidity, but rather relationship. For example, sin brings judgment, and judgment brings punishment or death; a ridged God then crushes and consumes. Our God proclaims judgment and allows reconciliation through repentance, thus relationship allows for restoration.
We can see this concept by reading the rest of the verse, it says, “therefore ye sons of Jacob are not consumed.” Reading before and after verse 6 we see that by all rights God’s people should have been fully consumed, but because of His unchanging nature, He gives all a space to repent (Revelation 2:21).
So then, what is the nature of God? He is love (I John 4:8), faithful and true (Revelation 19:11), merciful and just (Psalms 116:5), holy (I Peter 1:16), our Father (Isaiah 9:6), righteous (Psalms 145:17), and the list goes on, but let us not forget He is a judge (Psalms 75:7). With all the attributes inherent to his nature, He judges all mankind. Thus, His unchanging nature provides a plan of salvation to escape what we deserve.
Final thought… I could write a book about the implications of the one, true unchanging God, but it shall suffice to say that sin should not reign in our lives, but if you have found yourself in a state of failure, you can relocate to a different demographic. He never changes. Don’t lose faith as some, you are never beyond the reach of the one who never changes. It is in the nature of man to remember, but Jesus forgives and forgets.
“For I will be merciful to their unrighteousness, and their sins and their iniquities will I remember no more” (Hebrews 8:12).