Often an attack on Calvinism is related to John Calvin or Augustine as flawed individuals. But there is a problem with this argument, it’s not reality that the doctrines of grace come from John Calvin or Augustine. They come directly from Scripture.
When people attack Calvinism based on men that also held these doctrines it means they do not really have an argument at all. They don’t know that the doctrines come from Scripture and were not invented hundreds of years later.
Calvinism (with respect to soteriology) is just another word for Biblical Christianity. Plain and simple.
The doctrines of grace are found all throughout the Scriptures. But just read the book of Romans, or the Gospel of John. If you cannot see them it is because you are actively denying them.
In John we see the depravity of man. Nobody can come unless it is granted by the Father. The Father draws them (literally drags) to the Savior. Nobody can pluck them out of His hands. Do these concepts sound familiar? Of course they do. They are the doctrines of grace and they are all in John’s Gospel.
God will have mercy on whom he chooses based on nothing but his good pleasure and his glory. We are predestined for justification and adoption. Does this sound familiar? Of course they do. They are the doctrines of grace and they are all in the Letter to the Romans.
The idea that these beliefs did not show up until centuries after the New Testament was completed is simply not true. They come straight from the pages of Scripture and not from the minds of men.