I think the seven letters were to His Church on the seven continents. There are seven continents, you know. His Church will spread the whole Earth.
This is what happens when you read the Bible with an agenda of disliking Catholics. If you read with a mind open to other than that, you will see there is an obvious answer.
Christ prayed for unity for HIS Church. His perfect prayer would always be granted. Protestantism is not unified. Therefore, it is not Christ’s Church. Man created Protestantism. Those of us with the oil in our lamps have been faithfully waiting for Christ in the Catholic Church since Day One. Just as He told us to do.
The key thing is to actually read the Bible! That way you will know that the letters are to the seven churches in Asia. They were real places and we actually know where they are.
There are those who see a resemblance between the churches and the progression of the church structure during the past two thousand years. The Church established by Constantine is the corrupt church and the church established by Luther is the dead church. Read them again and see what you think.
It never ceases to amaze me how Catholics seem to think that any actual discussion of the Bible is an attack on the Catholic Church, while they blithely accept the Liberation Theology proclaimed by the current Pope.
You THINK??
In 1853 Tsar Nicholas I of Russia described the Ottoman Empire as "the sick man of Europe".
Not to worry.
The 'Mary' that Rome has created will give you solace until that day arises.