In Matthew 16:18, when Our Lord says to Peter: “You are Petros & on the Petra I will build my Church”, people tend to focus on the need for a masculine version of Petra because the person receiving the name is male.
Could it be the other way around, however? “Petros” has to be “Petra” (feminine) grammatically, in order that the Subject could say “I will build my Church” on this Object?
In other words: with Greek, does the feminine version of a word indicate a passive participle? Petros becomes Petra only because the Petros is the one on whom the building is built by the architect - thus, a passive recipient of the act of building?