Unfortunately, after the passing away of Umar bin Abdul Aziz (may Allah be pleased with him), the Ummayid ruling family returned to it's old ways of lavishness and excessive love of worldly pleasures. However, Allah (swt) blessed the ummah of prophet Muhammad (peace be upon him) with pious scholars and people of dawah who stood against this wave of materialism to remind the people of the true essence of their deen.
Of those great scholars of that time, Sheikh Nadwi singled out Imam al-Hasan al-Basri (may Allah be pleased with him).
His early days
He was born 21 A.H. His father Yasar was the servant of Zaid bin Thabit, the companion of the Prophet (peace be upon him). His mother Khayyirah was the servant of Umm Salamah, the wife of Prophet Muhammad (peace be upon him), and it is in her house that al-Hasan grew up and met many of the companions (may Allah be pleased with them) and heard from them, making him of the greatest of the Tabi'een (followerd of the companions).
His knowledge and passion
He had vast knowledge of the Quran and Hadith. Moreover, he was attentive to the details of the society he lived in: its different classes, manners, illnesses and cures. He was also a very articulate and charismatic person, one who captures and moves people with his words. Most importantly, his passion, sincerity and eman were what made his words sink right into the hearts of the people. Al-Ghazali describes him as "one whose words are the closest to the words of the prophets (peace be upon them), and whose guidance is the closest to that of the companions (may Allah be pleased with them)."
His method of dawah
Al-Basri's advise to the people revolved around reminding them of the shortness and treachery of this life, and the ever-lastingness of the Hereafter. He described in his talks the times of the companions and compared it to his time, and how much the faith and manners of the Muslim ummah had deteriorated.
He also displayed courage in facing the rulers with the truth and reminding them of their duties and responsibilities for which they will one day be held accountable by Allah (swt).
Al-Hasan al-Basri was not just another scholar or man of dawah who lectured or gave classes. He combined practical tarbiyah (disciplining/upbringing) with spiritual tazkiyah (purification) and was able to guide many to live the true Islam and taste the sweetness of Iman.
He passed away in 110 A.H. in Damascus. It is narrated that his funeral was after Friday prayers and that all the people were busied by it that day to the extent that 'asr prayer did not take place in the city's masjid that day because there was no one left there to pray.
May Allah (swt) be pleased with him and bless us with some of his sincerity and passion for guiding the Muslim ummah to the straight path, ameen.