I refuted Calvinism in the last 20 posts.
and you posted this..
4 To an inheritance incorruptible, and undefiled, and that fadeth not away, reserved in heaven for you,
5 Who are kept by the power of God through faith unto salvation ready to be revealed in the last time.
So, the inheritance is based on the Cross, and on being born again, but is separate from the walk of faith that occurs on Earth.
This is the same understanding as....>"will be conformed into the IMAGE of Christ"< as that happens after you die.
That is what is "predestined", and Calvin changed that into, "God predestined some to be chosen".
So, he totally changed verses to suit his demonic theology.
Your other verse, that is dealing with "The gift of Salvation", is understood as..
"Faith is counted as righteousness"....which has been done.
Proof?
The person is born again., as that is the PROOF that God has accepted their faith, already to give them the new birth.
The false teaching would be.
"if you hold unto your faith, you dont lose your salvation", as that person is trusting in FAITH, instead of trusting in Christ.