If all cells die, what is the origin of evolution?

I don't know. It's hard to precisely determine the origin of evolution.

Not all cells die. Some divide into daughter cells, and both of those cells have a chance to go on to produce more cells. Every currently living cell traces back along this unbroken chain of life.

The moment one cell became two, evolution began. The two cells were not perfectly identical. One would have had an advantage over the other. That one would produce more progeny than the other. As cells died, for any reason, lineages were culled. As cells reproduced, limited resources would provide challenges. The lineages would face three fates: outcompete for resources, find alternate resources, or become extinct. Over time, successful traits will accrue.

Yes, all cells die, but most reproduce before they die. Some of the cells are more successful (they have more living offspring). That's the basis for evolution.

Biological evolution is defined as any genetic change in a population that is inherited over several generations. Consequently it is the fact that cells die that drives evolution,

Known as the Primordial Soup Theory, it states that life began in a warm pond or ocean from a combination of chemicals and some form of energy. This led to the creation of amino acids, the building blocks of proteins, which would then evolve into all the species. This is suppose to have happened at least 3.8 billion to 3.55 billion years ago.