Perhaps God never changes, but the way he portrayed changes. The New Testament authors wanted a loving God; many of the Old Testament authors wanted a harsh and judgemental God in order that religion dominated the thoughts of the people.
People were filled with the Holy Spirit.
The new testament is not one whole book but rather a collection of books written by a few different people. No one "discovered" it, because it was never lost.
a leopard never changes its spots
You can never really count, it always changes
the climate never changes
There are many commandments and instructions in the Old Testament, including the Ten Commandments. God says He never changes, He's the same yesterday, today and forever, so the commands and instructions are applicable to us today.
Never heard of such a saying.
The speed of light in a vacuum never changes.
Joseph Stalin had informers in among Lenin's secretaries who told him about the Testament. Stalin got control of it and never let it be published.
The Old Testament never actually mentions Jesus Christ.
the atomic number never changes
None. Jesus was not in the Old Testament Books