The Hebrews and their God fast forward us to the 2nd Century A.D., when in Rome, prompted by early Christianity's "love for the dead,"(5) a vast system of caverns were being dug. Called the catacombs (the early word was coemeterium, a place of rest), the process would continue for over 300 years. As Roman Law forbid the dead to be buried within the city limits, the galleries were laid out from 33 ft. to over 49 ft. below the surface of suburban Rome, in the middle stratum of tufa, which is a soft igneous horizon.(6)

Why this love for the dead? These Christians fervently believed that, like their savior, they would someday rise bodily from their graves. So that, unlike their pagan countrymen who preferred cremation, Christians sort to preserve their bodies as best they could.(6)

In Rome alone more than sixty multi-level catacombs have been excavated, galleries that extend for hundreds of miles. Catacombs, which became underground churches, housing the bodies of martyrs, with their own art, relics, and graffiti, have also been found in Naples, Bolsena, Sicily, and North Africa. 

In June 325, a council of bishops convened, with the Emperor Constantine, who had converted to Christianity, in turn, making it a state religion, attending. Here the so-called Nicene Creed  It carefully identifies the Son with the Father, and thus states that Jesus was born the Christ, rather than becoming the Christ, "begotten, not made." Now God was as autocratic as the emperor, or as the Church. The Nicene Creed also outlaws concepts such as preexistence, reincarnation, and salvation through union with God were, although it took another two hundred years for these ideas to be completely expunged.

With the sack of Rome by Alaric in 410 A.D., then by the Goths in the 6th century, and later by the Lombards, the catacombs were abandoned to nature, which obstructed entrances with landslides and vegetation until their very existence was forgotten. Then, on May 31, 1578, a sepulchral chamber was discovered. Amazed at the existence of buried cities, an era of rediscovering the catacombs began.