Food and water are the necessities of life. We need them both to stay alive and for our bodies to grow and develop properly. They both contain the nutrients our bodies need to sustain life.
Jesus tells us that when we come to Him we will no longer feel hungry or thirsty. (John 6:35). He gives life to the dead and provides all we need to grow in godliness. The Spirit given at salvation and dwelling in us is the nutrient that enables us to develop properly.
Come to Him and everything needed will be given.