Calvinism is often portrayed as the standard of historic Christianity, but is this true?
If we imagine that Christianity started in the 16th century we might be able to make that claim. This is when its doctrines were widely embraced, and some of them were created. But of course, the Church of Jesus Christ began in the 1st century.
Calvinism’s distinct doctrines consist of the TULIP acronym, namely Total Depravity, Unconditional Election, Limited Atonement, Irresistible Grace, and Perseverance of the Saints. 3 of these doctrines were created by Augustine in the 5th century. Before that, Christian writers did not teach these doctrines. These 3 doctrines were Total Depravity, Unconditional Election, and Irresistible Grace. Though Augustine invented them in the 5th century, they were not embraced by many until the Reformation. Luther and Calvin accepted and promoted these doctrines. But until then, most Christians had rejected them.
The other 2 doctrines, namely Limited Atonement and Perseverance of the Saints were not heard of until Calvin’s day. And in fact, it is debatable whether or not Calvin himself held to the doctrine of Limited Atonment. Some argue that it was created later by his disciples.
So Calvinism is only historic and orthodox if we change the definitions of the terms orthodox and historic.
This is discussed more in this video: