Since young, Ustaz Zhulkeflee studied under many traditional Islamic teachers and was tutored by well-kniwn religious scholars in Singapore such as Kyai Muhammad Bin Muhammad Said Semarang, Kyai Shukur Bin Sulaiman, Shaikh Muhammad Bin Abdullah Diab ans Shaikh Abu Bakar Bin Ali Bahashwan. A combination of exposure to both educational systems - having studied in the English school and learning the deen through talaqqi approach via homeschooling after school hours - was what developed him.

In 1982, he was interviewed by the then-Mufti Syed Esa Bin Semait together with the late Al-Fadhil Al-Ustaz Syed Abdillah Al-Jufri and was approved and appointed by them to teach Islam in English. As a perpetual student of Islam, his continuous involvement in Islamic work as teacher, lecturer and trainer and the opportunity to meet and learn from other learned scholars and teachers such as Ustaz Ahmad Sonhadji, Ustaz Abu Bakar Hashim, Ustaz Syed Abdillah Al- Jufri, Moulavi MH Babu Sahib and Prof Syed Naquib Al-Attas, had added to his development and had given him much experience.

He has been involved in Da’wah and Education since 1980s and has worked with Darul Arqam Singapore (Muslim Converts’ Association of Singapore) and PERGAS (Singapore Islamic Religious Scholars and Teachers’ Association) and assisted in various activities of mosques, Syariah Court, MUIS, Family Service Centres, schools and associations. His fluency in English, alongside his deep training in the traditional Islamic sciences, made him a much-respected figure and he was appointed by MUIS to teach Islam to the Catholic seminarians at St. Francis Xavier Seminary and Singapore Pastoral Centre of the Catholic Archdiocese. After almost 64 years in serving Islam tirelessly at various levels, he breathed his last on 9th March 2017. In 2019, he was featured in the 3rd series of PERGAS’s Obor Ummah, in recognition of his selfless service to the Muslim ummah.