During the ceremony, which commemorated the feast of Mithras and the Sun following the sacrifice of the bull, followers of the Cult of Mithras share wine and bread in remembrance of their seven-stage initiation process.

Shrine to the god Mithra – the remains of antiquity. There is a shrine to the Mithras (mithraeum) from the second and third century AD not far from the airport in Špilnik, about 2 kilometers from the road to Gospić, where the worshippers of the god Mithras presented sacrifices and carried out cult pagan rituals.

In terms of the quantity of mithraeums in Croatia, the Gacka region comes in second place behind Salona, which is close to Split. In addition to this shrine, there are three others: one on the slope of Godača in Sinac, one on Rajanov grič in Čovići, and one relief panel that was previously discovered in the stone fence of the parish house in Sinac and is now housed in the Archaeological Museum in Zagreb. The pagan god Mithras is mentioned on several additional stone fragments in addition to the ones mentioned above because it is believed that he was born from stone.

In late antiquity, Mithraism was also popular in the ​​Gacka region, where it was brought by Roman slaves, merchants and craftsmen. Mithra's shrine on the King's throne is carved in living stone, and the relief depicts the most important event of Mithra's cult - the tauroctony, i.e. the moment in which Mithra kills the bull. Mithras is depicted as a young man in Phrygian dress kneeling on a bull, holding it by the nostrils.

Rituals were held in front of Mithra's sanctuary, about which little is known today because they were a strictly guarded secret.

This religion was reserved for men only, and the members of the cult were related like brothers.

Followers of the cult went through seven stages of initiation, and during the ceremony they partook of wine and bread in memory of the feast of Mithras and the Sun after the sacrifice of the bull.