Doc Holliday said:
I've heard many claim sanctification is the evidence of justification, therefore no works indicates no justification, it begs the question: did God then fail to justify? How would one know? And when would one know?
It's epistemically inaccessible to have assurance of salvation because you have no reliable self knowledge or external verification if your faith is real.
God, to a Calvinist, deceives...
From Calvin: Institutes of the Christian Religion (Book 3, Chapter 2).
"Evanescent grace is a theological concept primarily associated with John Calvin's writings, referring to a temporary or fading form of grace that God supposedly grants to some non-elect (reprobate) individuals."
"In this context, it describes a non-saving, illusory grace or faith that mimics true regeneration for a time (allowing the person to experience conviction, joy in the gospel, or apparent belief), but later dissipates, leaving the person without salvation."
Next question: how can you know you have saving grace and not evanescent grace?
"For God so loved the elect that He gave His only begotten Son, that whoever was already elect would be regenerated so they could believe in Him and would not perish but have everlasting life." John Calvin 3:16
If salvation is entirely monergistic and you had no real part in receiving it, the only way to verify your elect is to inspect the fruits. So you spend your life forensically auditing your own spiritual state trying to determine if your faith is the real God-given kind or the fake kind that looks identical from the inside. Everyone continues to sin their entire life: this is why the Calvinists report the most anxiety about salvation.
Sanctification is the evidence of salvation, but not all sanctification is externally visible in the form of works.
Sanctification is separate from justification. It's possible that it may be minimal to none in a justified person depending on the situation. The tax collector in Luke 18:9-14 who merely repented in his heart was justified, before any act of sanctification. If he had died right on the spot, though he had no sanctification, Jesus himself tells us he was justified.
Not all assurance of salvation is faith, but all faith is assurance of salvation. Absence or denial of assurance means there is no faith. So while it is possible that a person with "assurance" may not have true faith and therefore not have salvation... a person without assurance definitely does not have faith and therefore does not have salvation.
Someone who struggles to know if they have saving grace or "evanescent" grace and therefore is always unsure about their salvation does not have assurance, and therefore does not have real faith. They're focusing on their own righteousness rather than on Jesus' righteousness in their stead. They haven't truly understood the gospel. The question is: how is this any different from Roman Catholics or Orthodox?