In order to exist, life requires cells to multiply rapidly to support the larger organism, and enzymes make this possible. Without enzymes, life wouldn't have had the opportunity to evolve in the first place.
Within all the cells of living creatures, enzymes play the roll of a catalyst in cellular metabolism. This allows reactions to occur in milliseconds that would normally take eons. When scientists calculate the reaction time needed without enzymes for essential biological reactions in living cells, the result is often on the scale of millions and even billions of years. The reaction required to turn deoxyribonucleic acid (DNA) into ribonucleic acid (RNA) would take 78 million years to complete alone without the aid of enzymes. With no ability for the cells to copy genetic information rapidly, any life that occurred in these conditions would change so slowly that evolution would not have been able to occur.
Long after enzymes were formed and kick-started complex life, they still are essential for all necessary biological reactions to occur. The synthesis of both chlorophyll and hemoglobin, two molecules essential for both plant and animal life, would take 2.3 billion years to form without catalyzing enzymes speeding up the process. It is an ongoing debate in the scientific community how enzymes themselves were originally formed. Evidence suggests more primitive cellular metabolism used minerals from the environment for reaction catalysts instead of enzymes. The enzymes formed from these reactions could be used as catalysts themselves from that point on.