The concept of faith (إيمان) comes from the root أ-م-ن which also relates to safety and trust.
Key vocabulary:
- آمَنَ (āmana) = he believed
- إِيمَان (īmān) = faith/belief
- مُؤْمِن (mu'min) = believer
- أَمَانَة (amānah) = trust
The opposite is كُفْر (kufr) from root ك-ف-ر meaning to cover/reject.