In this series, Ustaadh Rayaan goes through the treatise The Four Principles written by Shaykh ul Islaam Muhammad ibn Abdul Wahaab. They relate to Tawhid and Shirk.
Tawhid refers to the fact that there is none who has the right to be worshipped except Allah alone, and that is the purpose behind the creation of humankind and Jinn as well as the primary purpose behind the sending of the Prophets and Messengers.
Shirk is the opposite of Tawhid and its nullifier. It is to direct worship to other than Allahh. The author states the grievous sin of Shirk and how many Muslims in later times fell into polytheistic practices such as supplicating to the deceased in their graves and depending upon them for salvation.
The principles are not based upon mere personal deductions, rather they are taken from the Qur’aan and the Sunnah of the Prophet ﷺ.
Below is the study booklet for these lectures which you may download and make your own notes:The 4 Principles Workbook 2017