How does one respond to an innovator who claims that their narrations are authentic due to the presence of trustworthy men whose reliability was attested to by their scholars, even though almost all of their narrations are weak?

The People of the Sunnah (Ahl al-Sunnah) judge the authenticity or weakness of hadiths based on precise and regulated principles and rules, and the isnad (chain of narration) is a fundamental pillar of the religion. As for the People of Innovation (Ahl al-Bid'ah), their hadiths often rely on weak or fabricated narrations. Scholars who are familiar with their books must engage with them to prove the weakness of their narrations. If an innovator presents an authentic text, he must be required to explain its meaning from the words of the Salaf (pious predecessors) of the Ummah.