For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord.(Romans 6:23) KJV
What does it mean that there was no death before sin? There are a couple of issues here.
- What is life?
- What is dying?
Firstly we have to know what the Bible considers to be alive. In our model of Earth formation gravity was created on the second day. This initiated what we refer to as the core accretion model which included the burying of Precambrian fossils. This was biological life which died before the fall of man, but it wasn’t Biblical life. Biblical life is a creature which breathes and has a soul.
We all have the same evidence. Our choice of paradigm determines what we think it’s evidence of.– Matty’s Razor
Secondly, what is dying? Is dying when we suddenly keel over because our metabolic processes stop? Or is it something which is ongoing, slow, sequential, inevitable, but not instantaneous?
Our bodies are made of cells. Cells contain DNA which encodes the information necessary for our life processes. If there was no death until the fall then Adam then he was living with the same cells that God had created him with. None of them had died and been replaced through cell division. After Adam ate of the tree of knowledge God’s prophecy dying thou shalt die, came true. The process of senescence began. His cells began to wear out, die, and have to be replaced.
Cells are replaced by a process of cell division called mitosis. Mitosis isn’t perfect. Every division of cells requires the replication of DNA. This process isn’t perfect either. DNA replication allows translation and copying errors to accumulate. This causes the loss of function of some genes, or may increase the activity of others. As a result of the accumulation of DNA copying errors and mutations over generations of cells, we get old, sick, and die.