The Forty Hadiths of al-Nawawi On the authority of Abu 'Amr And it is said, Abu 'Amrah Sufyan Ibn 'Abdullah al-Thaqafi, may Allah be pleased with him, said: I said, "O Messenger of Allah, tell me something about Islam that I need not ask anyone else about after you." He said: "Say: 'I believe in Allah,' then remain steadfast." Narrated by Muslim. This hadith encapsulates the reality of the religion in two magnificent phrases: Sincere faith in Allah, and then constancy in His obedience and uprightness upon His law. For faith is not merely a statement of the tongue; rather, it is a practical commitment that manifests in worship, character, and daily conduct. Uprightness means the persistence in obedience and the abandonment of disobedience, along with sincerity toward Allah. It is the path to salvation and happiness in this world and the Hereafter, because the greatest need of the believer after knowing the truth is to remain steadfast upon it.