Which one is the True Church?
Regarding churches claiming apostolic authority, particularly the Catholic/Protestant divide, something that is overlooked is that worship was centralised on earth but this ended in AD70. It was possible for Satan to roll the political power of Rome into bed with the religious authority of Judaism, and bring both systems down upon all true worship as persecution.
Since that time, the centre of true worship is in heaven. It is now impossible for Satan to corrupt or attack its centre because the new Jerusalem is above. We see this in Revelation 2-3. Not only is the menora now split into seven separate lampstands, the lampstands are in the holy place, seated with Christ.
So, when the Roman church became corrupt, God’s people came out. When protestantism becomes corrupt, God’s people come out. As Christianity declines in the west, it is booming in the southern hemisphere. Satan is bound from mounting an all-out worldwide attack on the church until he is released for a short time, and then only so he can be drawn out of Egypt like Pharaoh to be destroyed.
There is an institutional church, but in her visible form she is only ever local assemblies. The ‘city of God’ is in heaven, incorruptible, unassailable. If her earthly ‘branches’ leave the vine, they wither up. When they have only darkness to share, Jesus snuffs them out. They are no longer ‘the church’ regardless of whether the physical institutions remain.
Magisterially, the church governs from heaven. The new Jerusalem will descend at the end of history, but any attempt at a centralised, earthly city of God before then is doomed to failure, Roman Catholic or otherwise.