What is the significance of homeostasis?

Homeostasis is critical for maintaining a stable internal environment in living beings so that normal physiological processes can proceed efficiently without any interruption. It allows the body to function efficiently notwithstanding changes in the environment or other external factors. 

Any interruption or failure in the homeostatic regulation in any of the body systems can cause an imbalance in the internal environment, which adversely affects normal functioning of the system and can result in illness or even death.