al-ʿAllāmah ʿUbayd Ibn ʿAbdullāh al-Jābirī is the eldest of al-Kibārul-ʿUlamāʾ (the major scholars) of this Ummah. In this beneficial phone lecture on the topic of al-Uṣūl ud-Dīn (The Foundations of the Religion) he admonishes the attendees on the topics of Tawḥīd and Kufr, Waajibaat (obligations) and Ḥarām (unlawful), Kufr al-Akbar (the major disbelief) and Kufr al-Asgher (the minor disbelief).
From the Lecture:
“From the foundations of the religion is to submit to Allāh with tawḥīd and to comply with obedience to Allāh and to be free from the people of Shirk (polytheism).”
“It is founded upon two foundations; they are the foundations of the religion. The Religion will not be established without them. Shaykh al-Islām Muḥammad Ibn ʿAbd al-Wahaab (raḥimahullāh) mentioned them, ‘The ‘Asl (foundation) of the dīn are two affairs, the first is the daʿwah or call to worship of Allāh alone, to encourage that an align oneself with that and to make takfīr of the one who leaves that, to be harsh upon the one who opposes it.’”
“The proof for these two fundamentals is katheer (many) in the Qurʾān. Indeed we have sent to every nation, saying worship Allāh and don’t worship false Gods’ and ‘We did not send a messenger before you except that we informed him to worship Allāh and not worship other than him.’”
“The one who analyzes these verses (in their meaning) o my sons and daughters will understand the wājibaat (obligations) of having ikhlās (sincerity) in singling out Allāh in Worship. All of the daʿwah of the messengers singled out Allāh in worship.”
“The greatest of that which Allāh has ordered is Tawḥīd and the greatest of that which he has prohibited is Shirk and there is no Dīn acceptable to Allāh except Islām.”