There is nothing negative about pointing you to the truth. Indeed you should have been thankful.
Christ is the only Rock and Foundation upon which the Church is built. And Peter's confession (obtained by divine revelation) -- that Jesus is the Christ, the Son of the living God -- confirmed that. Therefore the Church is the Body, the Bride, and the Building of Christ.
Enoch: I do accept and agree with your explanation because...new believers are those that believe and trust that salvation is through Christ. They become in Christ as Christ is in the Father.
God announced and revealed to Peter the identity of the human instrument or direct object for salvation, Jesus, his son. He would now be the instrument by which salvation was possible. Previous to his son's birth, death, resurrection and ascension, God himself was the direct object of salvation as per over 24 verses in the OT, under the Law.
God announced the transfer and new way to salvation from himself directly to his son, under grace.
Since Christ is in the Father, the Father is the ultimate savior of men and they are the ekklesia (living stones) of Christ (living rock), for the Father (enormous living rock).
Bless you,
APAK