We have already discussed that. I do not follow calvin
You can not study scripture and realize that salvation is eternal. So you may disagree with the term Calvin uses (perseverance of the saints) but you have to agree with the precept. That who ever is saved and has been given eternal life is saved, period.
But it has zero to do with the person persevering to the end of anything. The Holy Spirit has sealed the believer for the adoption, the redemption of the body.