Shaykh al-Islām Muḥammad ibn ʿAbd al-Wahhāb’s mentions in his letter to ʿAbd al-Raḥmān al-Suwaydī (one of the scholars of Iraq at that time):

I convey to you that I am a follower and not an innovator. My creed and religion that I worship Allāh with is the methodology of Ahl al-Sunnah wa-al-Jamāʿah which the leaders of the Muslims were upon, like the four Imāms and those who follow in their way until the day of judgement.

Likewise, I have clarified to the people (the importance of having) sincerity towards the religion for the sake of Allāh, and I have forbade them from calling upon the dead or the living and associating them as partners with Allāh in acts of worship the likes of slaughtering (sacrificial animals), making a vow, having reliance and trust, prostrating and other than this from the rights of Allāh that no angel or messenger has any right to be associated in with Allāh. This is what all the messengers—from the first of them to the last of them—have been calling to, and this is what Ahl al-Sunnah wa-al-Jamāʿah are upon.

Source: Majmūʿ Muʾalafāt al-Shaykh Muḥammad ibn ʿAbd al-Wahhāb 5/36
Translated by: Munīb al-Ṣumālī