Barefoot have several meanings. For example, nakedness of feet is a sign of mourning. God says to Ezekiel, the priest (Ezekiel 24:17) Make no mourning for the dead...and put on thy shoes upon thy feet. David is said to have gone from Jerusalem barefoot, when he fled from Absalom. It is also a mark of respect. In the Koran we find the passage Surely I am your Lord, therefore put off your shoes..."(Ta Ha 20:12). The Muslims do indeed leave their shoes at the door of a mosque before entering. In Christianity we find that Moses took off his shoes to approach the burning bush where the angel of the Lord called to Moses (Exodus 3:5); priests serving in the Tabernacle (a tent sanctuary used by the Israelites during the Exodus) did so with their feet naked, as they did afterwards in the Temple. This is likely what is referred to in our rituals.
The foot is said to represent the soul, as it serves to support the entire body and keep it upright. Demonic beings, for this reason, were often depicted with feet that differed to those of man, or were turned the wrong way.
The foot being planted upon the earth, signified to many that the foot left a personal emanation of that being on that spot, especially in Buddhism where footprints, purported to be left by the Buddha, are revered in several places. Perhaps this is one explanation why we admire those Hollywood stars' hand and footprints? Ancient cultures throughout the world put significance to many rock formations (often of natural origin, such as erosion) that looked like footprints, or hollows of feet that had been left there, often interpreted these as those left by holy, or supernatural beings. The mother to the founder of the Chinese Chou dynasty was said to have become pregnant by stepping on a stone that had a foot imprint of a God - which also linked the child-to-be-born to the divine. It is for a similar thinking that explorers were able to claim entire territories by merely "setting foot upon it".
One direction Pythagoras gave to his disciples was "Offer sacrifice and worship with thy shoes off." Maimonides, the great expounder of the Jewish Law, asserts that "it was not lawful for a man to come into the mountain of God's house with his shoes on his feet, or with his staff, or in his working garments, or with dust on his feet." The Druids also practiced this by performing their rites barefooted, as did the Peruvians before they entered the temple to worship the Sun.