The Bible, especially Paul, doesn't state that Christ's death, which was your death, and Christ's resurrection, which was your resurrection, was provisional.
Let's go to Hebrews 9:25 "Nor did He (Christ) enter to offer Himself often, as the high priest enters the Most Holy Place every year with blood that is not his own. 26 For then He would have had to suffer repeatedly since the world was created, but now He has appeared once at the end of the ages to put away sin by sacrificing Himself."
If you were saved when you believed then Christ "would have to suffer repeatedly", i.e., He would have to die again and again for everyone who believes.
Faith is a response to what Christ has already accomplished. Christ death, which was your death to the law, happened once for all men.
Clearly Calvin was in error.....