Explanation of the Three Fundamental Principles
From the book:
These matters require from the believing man and woman, young and old to learn.
The author (May Allāh have mercy upon him) said,
“The first is knowledge” one is obliged to learn and gain insight so that he is upon clarity. He must learn about the religion of Allāh which he was created for. This knowledge is learning about Allāh, His Prophet, and the religion of Islam with proofs.
So, that is the first matter that the servant gains insight about who is his Lord?
Hence, he learns that his Lord is the Creator who created him, provides his subsistence, and confers His favors upon him. Allāh created those who came before him and those who will come after him. He is the Lord of all that exists. Allāh is the one true deity and object of servitude. No one besides Him deserves to be worshiped. Not a close angel, a messenger who was sent, not a Jinn, no human, no idol or anything else deserves to be worshiped; Rather, true worship is a right that belongs to Him alone. He is the sole object of worship in truth.
He deserved to be worshiped. He is the Lord of all that exists. He is your Lord and Master, your Creator, and your true Deity. So, you should know this first matter which is knowing your Lord, your Prophet, and your religion with proof. It is what Allāh says, and his Prophet said, not by opinions and statements of so and so person. Instead, it is with proofs from the verses of the Qurʾān and Ḥadīth. This is the religion of Islam that you have been obliged to enter and commit to.
It is the worship of Allāh which He (the Exalted) says about it,
“And I (Allāh) created not the jinn’s and humans except they should worship Me (Alone.” [Sūrah Adh-Dhariyat 51:56]
This worship is Islām. It is obeying Allāh and His Messenger. It is establishing Allāh's orders and abandoning forbidden matters.
This is the worship in which mankind was created for. Allāh orders this within His statement,
"O mankind! Worship your Lord (Allāh). ” [Sūrah Al-Baqarah 2:21]
Meaning: worship Him by obeying His commands and abandon His prohibitions, and submit oneself directly to him, and specify worship for Him (the Exalted).