God appointed Peter to head his church on earth. The Popes down the centuries are his successors.The first RCC codification of contraception wasn't until 195AD, by clement of alexandria. Peter would've been nothing but bones and ashes. There wasn't even a catholic church when peter supposedly lived.
"HE WHO HEARS YOU PETER HEARS ME".
Recap; God gave the Pope the authority to head his church and to make church decisions. His successors follow suit the way God intended and "the gates of hell will not prevail against it".
Catholic means universal btw.