I don’t think you know Calvinism because the 5th major tenet of Calvinism is ‘perseverance of the saints’ and it is the same as once saved always saved. The discriminating election of God, according to Calvin, makes it impossible for the elected and saved to lose his or her salvation.
Actually you have just proven you don't know the difference between the Biblical truth of "Perseverance of the Saints" and the easy believism heresy of "once saved, always saved."
Suggest you do some reading of prime source documents instead of the falsehoods of others, like the above hit piece.