Introduction about the better understanding of the healthy institutional sphere in which the ancestral religiousness took place.
The Hellen priest, with the exception of a few cases of family hereditary transferral of the clerical duty (e.g. Eumolpidai in Eleysina, Emvaridai in Piraeus etc) or a royal household (like what was happening in Sparta), obtains the clerical duty by elections from the assembly of Demos, a practice that dates back to the homeric days, or by draw (where the drawing acts like God or a simple indicator of divine will).
The Hellen priest is not the representative of God on earth, like all monotheistic religions and theocratic regimes were, and still are, alleging about their religious priestcraft, but quite the contrary he is simply the elective representative of the adorers, authorised either to minister the Temple in which he is placed (as an «archiereus» - a high-priest) or to perform the sacrifices (as a «hiereus» - a priest) or to chant blessings and prayers (as an «areter» - the one who says prayers).
The clerical post is not tied up to a specific age, sex or class. Men and women, rich and poor, young and old, everyone has the right to be elected as a priest, and each priest upon leaving the duty, in contrary to the clergy of several other religions and within the democracy concept of the Polis (city), has to give a statement of his actions and a financial report about the Temple (see Aeschines, Against Ctesiphon, 17-18).
Even though the priest is deeply respected by the people in no way he is considered saint or holy.
Besides, for the Hellen, holiness does not mean anything but the knowledge about what it takes to live peacefully and harmonically among people and the Gods.
Simple preconditions about undertaking cleric duties are the soundness of limb (and not physical perfection, since Ageselaos was lame but able in body and was elected king of Sparta and priest of Gods Zeus, Apollo, Athena and Hercules), the genuine ancestry and, mainly, the general appreciation about oneself, most importantly (s)he should not bear any of the «impurities» incongruous to the priestly status (for example irreverence, homicide, oath-breaking, betrayal etc).
During the hellenic ritual, the Hellen priest or priestess usually wears white dress, to denote purity (with the exception of the priests of Zeus who wear purple dresses and ribbon-made diadem bearing the colour of their God), or wreath made of tree or plant leaves that is considered sacred of each of the specific adoration. It should be emphasized here the remarkable fact that to the Hellenes, since homeric days, full right to the ritual (sacrifice, libation, prayer) had any of the adorers, whilst during the campaigns the army commanders equally undertook the commitment to perform the ritual and in the home-worship either husband or wife (according to the nature of the deity) officiated.
Thus by not considering the priest or priestess representative of God on earth, but a simple «priesting» citizen, the quality of the relationship to the honouring God or Goddess is a concern of all the citizens that attend the rite. What we have here is another confirmation of a strong, but idiomorphic Hellenic communalism that wants the individual inextricable part of the society but on the other hand also accountable for his own actions and personality.
Therefore the purity of the priest accounts also for the adorers, in the sense that one should be clean of serious impurity. Those who bear the mark of serious foulness cannot participate in the sacrifice if they haven't purged themselves before. «Unadulterated» should also be all those who just returned from war, all those who just recovered from sickness, all those who returned home after a long period abroad, etc.
That's why before the sacrifice the priest cries out «hekas, hekas, hostis alitros» (go away whoever is impure).
Vlassis Rassias, from the book "Festivals and Rituals of Hellenes"