The meaning of the English word “holy” is rooted in Proto-Germanic, Hebrew, and Greek. Etymologically speaking, the word itself is derived from the Old English halig which, in turn, finds its origins in the Proto-Germanic term hailaga and the Proto-Indo-European root kailo, meaning “whole,” “uninjured,” “safe,” and even “auspicious.” In that sense, the holy, the whole, and even the healthy are etymologically related: They all refer to a broad notion of salvation, even from disease and unrest.
But our everyday uses of the word holy certainly carry other overtones, inherited from monotheistic traditions. The Hebrew word qadosh, for example, has been commonly translated as holy – although it might be better translated as sacred (which is slightly different). In any case, qadosh conveys the idea of being set apart (that is, of being sacred) but also carries a sense of purity (that is, of wholeness, of not being polluted, of remaining uninjured.)
This notion is deeply embedded in the Hebrew Scriptures, where God is often described as “holy” to signify His absolute perfection – his wholeness and unity. Even though intimately related, the sacred is not always necessarily holy.
The New Testament uses the Greek word hagios to convey this very same concept. Much like its Hebrew counterpart, hagios denotes something set apart yet emphasizing its being fully (that is, wholly) dedicated to the divine. In Christianity, this term is frequently used to describe God’s character (Holy, Holy, Holy) and the sacred nature of spiritual entities.
Both the Hebrew and Greek emphasize two things: the separate nature of the divine, and also its wholeness. That is, the idea of holiness extends beyond a mere absence of impurity; it captures the inherent sanctity and perfection (wholeness, completeness, absoluteness) of God. Indeed, the journey of the term holy from its linguistic origins in Proto-Germanic and its incorporation of biblical (Hebrew and Greek) overtones to its current usage in English shows the continuity of religious and cultural concepts across different languages and civilizations.
