Traditionally, the Hierophant is the intermediary or interpreter between the worshiper and the their deity. Who ever or what ever that is. Before this century, most decks called him the Pope. To most modern readers, this is mostly a negative card, referring to the “Keeper of the Keys”–again the Pope, who was the only one who had the power to reach God.
In many modern churches and most Pagan and other modern religious systems, we find our own way to God/Goddess or Deity. The modern Hierophant directs us to look inside ourselves and see what is there. What WE are capable of. To see that we can directly get in touch with the greater Universe and find information we need. He is much more positive and pro-active..
The meaning of this card depends greatly on the Deck. My deck of choice, the World Tree Tarot shows the Hierophant as showing us the was to find the way to the Greater Universe for ourselves. Other decks, including another favorite, the Robin Wood, will show the Hierophant as a Pope, keeping the secrets to himself through theater and heavy handed rules.
This card reminds us again that there is no one true way. Each of us must figure out for ourselves how to, as one Rosemary Edghill put it so well, “unscrew the inscrutable.” It warns us not to get taken in by doctrine or rules or leaders that insist they know all the answers. If it comes up in a reading, the seeker is told to look for truths for him or herself. To look for Deity through rituals of their choice, meditation or prayer. We find Deity and truth by opening up our Inner Vision.