>>23344
>why didnt they just take him as the first and only pope?
Because near the same scripture Jesus Christ promises that the church built on Peter will prevail against the gates of hell.
18 And I say to thee: That thou art Peter; and upon this rock I will build my church, and the gates of hell shall not prevail against it.
So the Lord Jesus Christ promises that the gates of hell will not prevail against the Church.
So, the Church will last. It didn't end with the death of Saint Peter when Saint Peter was martyred.
Saint Peter passed on the leadership of the Church to Saint Linus. Now, what gave Saint Peter the authority to do that? Go to the next verse...
19 And I will give to thee the keys of the kingdom of heaven. And whatsoever thou shalt bind upon earth, it shall be bound also in heaven: and whatsoever thou shalt loose upon earth, it shall be loosed also in heaven.
The giving Saint Peter the Keys make him the head of the church in that Peter's judgement on faith and morals becomes Infallible and Indefectible. Whatever Peter says on faith and morals will be bound on Earth and in Heaven.
So if Saint Peter says, as a mater of faith, that Saint Linus inherits his chair, then it is so because the Lord Jesus Christ gave him that Authority.
The Church says, by the authority of the Popes, that no one can name a Pope who isn't Catholic and isn't ordained in the Church.