How do we know what the Prophet (peace and blessings be upon him), his Companions, and the generation following them were upon in matters of religion?

The Shaykh : How can we know what our righteous predecessors were upon? Whether it concerns creed, jurisprudence, or conduct, the path by which we know what the Messenger (peace be upon him) was upon is the same path by which we know what the righteous predecessors were upon. In short, it is the path of narration, the path of hadith, and receiving the narrations related to the Prophet (peace and blessings be upon him) or the righteous predecessors. It is through the path of narrations and hadith. The majority of Muslims today, and even before today for centuries, have deviated from this path. They relied on their own opinions in understanding the Book and the Sunnah, and they did not feel at all, deep within their souls, that they needed to seek assistance in understanding the Book and the Sunnah through the reports of the righteous predecessors. They did not feel this.