Understanding and application

How should a beginner understand فَلَيْسَ مِنَّا in this warning?

Humility, Gratitude, Goodwill, and Conditional Sentences (Hadith 188–198)

• Treating plunder as a trivial mistake
• A strong moral warning, not an instant verdict on a named person’s faith
• Assuming every sin is beyond forgiveness
• Denying that others have property rights