The Petros/Petra distinction in Greek does not exist in the Aramaic Jesus spoke

The most common Protestant grammatical argument against Petrine primacy runs as follows: in Matthew 16:18, Jesus says “You are Petros [masculine noun, meaning a small stone] and upon this petra [feminine noun, meaning a large rock] I will build my Church.” Therefore, Peter is only a small stone, and the rock on which the Church is built is something else — Christ himself, or Peter’s faith.

This argument depends entirely on a distinction in Greek that does not exist in Aramaic. Jesus spoke Aramaic. The Aramaic word for rock is Kepha — the name Jesus gave Simon at the beginning of his ministry (John 1:42). In Aramaic, Matthew 16:18 reads: “You are Kepha, and upon this Kepha I will build my Church.” There is no distinction. There is no “small stone” and “large rock.” There is one word, used twice, referring to the same person.

The Greek distinction is a grammatical necessity — Greek does not have a feminine masculine form for proper names, so Matthew uses Petros as Peter’s name and petra as the common noun. The theology is Aramaic. The grammar is Greek. Confusing the two produces an argument that only works in a language Jesus never spoke.