The Divisions of Tawhid and the Difference Between Shirk and Bid'ah

Question:
May Allah reward you, Honorable Shaykh. This questioner says: Is it said that tawhid (the oneness of Allah) has four types: tawhid al-rububiyyah (oneness of lordship), tawhid al-uluhiyyah (oneness of worship), tawhid al-asma' wa al-sifat (oneness of the names and attributes), and tawhid al-mutaba'ah (following the Prophet (peace and blessings be upon him))?

Answer:
No, tawhid has three types. No one has said it has four types. Following the Prophet (peace and blessings be upon him) is undoubtedly obligatory; this is the meaning of the testimony that Muhammad is the Messenger of Allah. As for the three types, they are the meaning of the testimony that there is no god but Allah. So the meaning of the testimony that there is no god but Allah is the three types of tawhid, and the meaning of the testimony that Muhammad is the Messenger of Allah is following the Messenger (peace and blessings be upon him). Contradicting the testimony that there is no god but Allah is called shirk (associating partners with Allah), and contradicting the testimony that Muhammad is the Messenger of Allah is called bid'ah (religious innovation). So one who contradicts the Messenger (peace and blessings be upon him) is an innovator, and he is not called a mushrik (one who associates partners with Allah). The Prophet (peace and blessings be upon him) said: a man, meaning his deed is rejected, it is rejected and not accepted. This is bid'ah; contradicting the Messenger (peace and blessings be upon him) is bid'ah, and contradicting tawhid is shirk. There is a distinction between them. The Salaf (the earliest generations) did not answer that tawhid has four types; they said it has three types. In the original understanding, they say there are two types: tawhid al-rububiyyah and tawhid al-uluhiyyah. Tawhid al-asma' wa al-sifat is included in tawhid al-rububiyyah. But when the Jahmiyyah (a sect that denied the divine attributes), the Mu'tazilah (a rationalist theological sect), the Asha'irah (the Ash'ari theological school), and the Maturidiyyah (the Maturidi theological school) appeared in the later centuries, who engage in ta'wil (figurative interpretation) of the attributes, they separated tawhid al-asma' wa al-sifat in order to refute them, although it is included in tawhid al-rububiyyah.
So tawhid originally has two divisions: tawhid al-rububiyyah, which includes tawhid al-asma' wa al-sifat, and tawhid al-uluhiyyah.