If catholics really believe you can lose your salvation, then every catholic should be camping out at the door of their priest and constantly confessing sins. Every single waking minute of the day, month and year. 7/24/365
The fear the catholic must live in not knowing if they are "in a right relationship with God" at death must be paralyzing.
Amazing that catholicism ignores Ephesians 1 where the Bible notes that "you were sealed in Him with the Holy Spirit of promise, who is given to us as a pledge of our inheritance with a view to the redemption of God's own possession to the praise of His glory." I cannot find anywhere in the Bible where we are ever unsealed; either by Him or our own efforts.
The Protestant obsession with “assurance” comes from Luther’s own neuroses.
Catholics do not live in the kind of fear you cartoonishly describe, because salvation cannot be “lost” in the manner you describe. It can only be rejected, deliberately.
The conditions for a mortal sin are: grave matter, sufficient knowledge/refection, and a free act of the will.
No one commits mortal sin unknowingly or by accident. “Salvation” cannot be misplaced like one’s glasses or car keys.
The words in Ephesians describe how GOD has committed himself to our salvation. Jesus has given his life in order to bring us the possibility of living in grace.
The words in Ephesians are NOT a description of OUR subjective psychological state.
Protestants would profit by a better understanding of how Luther’s warped, neurotic psyche led him to twist the gospel. Luther re-interpreted Scriptures describing GOD’s unshakable desire to save us into a description of SUBJECTIVE “assurance” about our salvation.