Please read Matthew 16:18.
Christ's church lives.
This is rather involved. During the three days Christ preached to the Dead. Thus he created a church for those in Spirit Prison to learn his Gospel. There is no other answer for this scripture. What reason was there to teach them if they were already damned as Catholic believe. Well there is an answer Paul tells us in 1 Corinthians 15:29 Now if there is no resurrection, what will those do who are baptized for the dead? If the dead are not raised at all, why are people baptized for them?
This is the real answer. The church did not end with John. It continued in the Spirit World with Peter himself at the Head just as promised.
God himself came down as Jesus Christ and paid the ultimate price for all his children. Every single one. No matter what church they belonged to they will all be resurrected just as he was. He being God knew the church would not last long upon the earth thus he taught about a second coming.
This has not happened yet but he is preparing the earth for this and has reestablished his church upon the earth with Apostles and Prophets. He himself at the head speaking to the Prophets as necessary. Apostles call new Bishops, Priest, Deacons and other Church Officials and pass on this authority to others to act in their name with their approval.
"The Church of Jesus Christ of Latter Day Saints" is this church the only true church on Earth.
But fear not if you are not a member you can still learn the gospel in the spirit world and someone here on earth can be Baptized for you. But better to join here on earth and do the work for your ancestors yourself.