The most powerful force in our solar system is the Sun. Through its intense light, the solar wind, and solar flares, the Sun influences everything around it. However, the Sun itself, and the way in which it influence its surroundings are not constant in time. The Sun varies on times of hours, by solar flares, on times of years, through the solar sunspot cycle, and even evolves slowly over billions of years. In this talk, I will discuss how and why the Sun changes with time and also how these changes affect our surroundings, and I will explain a paradox about the changing Sun that is at the heart of our understanding of how life emerged on the Earth.