According to search-discovered classical Islamic scholarship, hypocrisy (An-Nifaq) is a grave spiritual disease characterized by concealing disbelief (kufr) while outwardly professing faith (iman). Tafsir scholars like Ibn Kathir, analyzing the extensive Quranic discourse in Surah At-Tawbah and Al-Munafiqun, define the hypocrites (Al-Munafiqun) as an internal enemy more dangerous than external foes. Islamic theology makes a critical distinction between Major Hypocrisy (Nifaq al-Akbar), which nullifies faith and consigns one to the lowest depths of Hellfire as per Quran 4:145, and Minor Hypocrisy (Nifaq al-Asghar), which involves possessing traits like lying, breaking promises, and betraying trusts as warned in authentic hadith. The synthesis across dozens of verses and prophetic traditions presents Nifaq not merely as duplicity, but as a comprehensive failure of sincerity that manifests in mockery of religion, aversion to sacrifice, and treachery against the community of believers.