Originally, the 1st Amendment was written to protect Christian religious freedom. That is its original historical context. It was written to protect Christians in the colonies from the persecution of the Church of England, which was in the colonies, particularly Virginia. It is because of Christians that other religions enjoy religious freedom in the US.
The Constitution is not a living document that needs to be reinterpreted or changed. It simply needs to be enforced. It is the law of the land, as written. The Progressives (Communists) want to scuttle the Constitution and so we need to protect it from those on the Left who want to do violence to it.