H2O has unique properties that allow life to thrive. The angle between its two hydrogen atoms is 105°, giving each molecule a slight negative charge (δ– in the above illustration) on the oxygen end and positive charges (δ+) near each hydrogen. Consequently, individual molecules attract their neighbors, producing a “group feel.” This electrostatic attraction makes water a liquid at room temperature rather than a gas, as would be expected of such a light molecule. These hydrogen bonds (the dashed lines) also give rise to surface tension, enabling water striders to skate along the surface of ponds, and trees to draw water to great heights via capillary action. Because of water’s electrical imbalance it dissolves many kinds of substances, allowing it to transport nourishment and waste in our bodies. Water’s high specific heat (another consequence of hydrogen bonding) causes oceans to warm and cool gradually, moderating our planet’s temperature swings. No water, no life.
Hence, water makes memorable metaphors. “Whoever drinks the water that I give will never thirst … Like cold water to a weary soul is good news from a distant land … If anyone gives even a cup of cold water to one of these little ones who is my disciple, he will certainly not lose his reward … Christ gave himself up for the church to make her holy, cleansing her by the washing with water through the word.” Water—unique, vivifying, refreshing, purifying. Come, drink, enjoy!