The last part of your answer is nonsensical. The Church was already established before Roman Catholicism took it over. It started way back in the Old Testament among those who believe that God had someone who was coming to save them from their sins. Of course, the New Testament reveals our Lord and Savior, Jesus Christ, to be the One who saves us.
You wrote:
“The last part of your answer is nonsensical.”
No, it is not.
“The Church was already established before Roman Catholicism took it over.”
The Catholic Church is the Church.
“It started way back in the Old Testament among those who believe that God had someone who was coming to save them from their sins.”
No. Someone can certainly say that God planned the Church before all ages, but the Church was not founded or revealed to the world until the time of Christ. This is clear from Christ’s own words in Matthew 16 when Jesus says He WILL build His Church - meaning it did not yet exist.
“Of course, the New Testament reveals our Lord and Savior, Jesus Christ, to be the One who saves us.”
And He chooses to do so through the ministry of the Church - just as the New Testament makes clear in John 20:19-23 and other verses.