Epiousios (Ancient Greek: επιούσιος) is a unique Greek word found only in the Lord’s Prayer in the Gospels of Matthew and Luke, and nowhere else in all of classical Greek writings.
It has been translated to mean “daily” as in “our daily bread”, but perhaps we devalue the word and the concept when we think, metaphorically or literally, as this being a prayer for sustenance.
If the New Testament writers had meant “daily” there were more common words the could have used than epiousios, so it must have some distinct and special meaning above and beyond “daily”.
If Epi means necessary or essential, and Ousia means to physically exist, then Epiousia can be taken as necessary for existence, and Epiousios becomes that element that is necessary for existence.
If we think of this in terms of a creator, do we owe just our original manufacture to the creator, or is the creator responsible for maintaining ongoing reality as we know it?
Does reality exist independent of God, or is reality the ongoing product of God.
Are we God’s dreaming? Are we products of God’s mind? Is this the concept the word is attempting to express?