One day, Jesus took His disciples North of the land Jews felt comfortable in, to Caesarea Philippi. There, still today, is a cliff with a pool of spring water before it called “the rock of the gods.” On the day Jesus led the field trip, the water was flowing from a cave, and was called a “gate of Hades.” Such flows of water from underground were considered in Greek and Roman mythologies to be paths to the Underworld, where their gods spent winters, causing the earth to be neglected and lifeless. Springtime called for ritualistic sex and symbols of rabbits and eggs to invoke the gods to return to the surface of the earth and bless the crops and herds and wives with much reproduction and bounty.
In this place of pagan symbols and activities, Jesus responded to Peter’s God-inspired revelation that He was the “Christ – the Son of the Living God” with, “Happy art thou, Simon Bar-Jona, because flesh and blood did not reveal [it] to thee, but my Father who is in the heavens.
And I also say to thee, that thou art a rock (“petros” – G4074: piece of rock), and upon this rock (“petra” – G4073: mass of rock) I will build my assembly (“ekklesia” – G1577: authoritative assembly, called together), and gates of Hades shall not prevail against it; and I will give to thee the keys of the reign of the heavens, and whatever thou mayest bind upon the earth shall be having been bound in the heavens, and whatever thou mayest loose upon the earth shall be having been loosed in the heavens.”
(Matthew 16:17-19 Young’s Literal Translation / my parenthetical word explanations include numbers from James Strong’s Greek dictionary)
I quoted Matthew 16:17-19 using Young’s Literal Translation because it was not affected by instructions of James 1, king of England, to the men he employed to translate the Scriptures into English, which included the specific instruction to mistranslate “ekklesia” as “church.” His instruction was given so that he would have no threat of local “assemblies” perceiving their authority as gatherings of the King of Heaven. “Ekklesia” is a word that Jesus used 3 times in the Gospels. Each time, He was talking about His Kingdom, not about what Constantine in 330 AD or so and James in 1611 AD created and called “church.”