Even a fractional variance in the Earth's position to the sun would make life on Earth impossible. The Earth remains this perfect distance from the sun while it rotates around the sun at a speed of nearly 67,000 mph. It is also rotating on its axis, allowing the entire surface of the Earth to be properly warmed and cooled every day. And our moon is the perfect size and distance from the Earth for its gravitational pull. Water allows us to live in an environment of fluctuating temperature changes, while keeping our bodies a steady 98.6 degrees.
Water is a universal solvent.
Water is also chemically inert. Without affecting the makeup of the substances it carries, water enables food, medicines and minerals to be absorbed and used by the body. Water has a unique surface tension. Water in plants can therefore flow upward against gravity, bringing life-giving water and nutrients to the top of even the tallest trees. Water freezes from the top down and floats, so fish can live in the winter.