Eating, drinking, sleeping, fear and copulation are common to both animals and human beings. But that which makes a person a real man or a God-man is worship. Worship or spiritual practice transmutes a man into a blessed Divinity.
Lord Krishna says in the Gita: "But by devotion to Me alone I may thus be perceived, Arjuna, and seen and known in essence, and also entered into, O Paranthapa."
He who leads a mere outward sensual life without doing any worship is an animal only though he wears outwardly the form of a human being.
From "Daily Sayings" by Swami Sivananda (1987-1963). More Informations on Swami Sivananda
: on the Website of Divine Life Society
, Photographs of Swami Sivananda
, German Pages on Swami Sivananda