Ibn al Qayuim (rh) said:
So whenever Shaytan brought about an innovation from these newly invented matters, or from other than them, Allah established from His party an army—those who refuted it and warned the Muslims against it, all for the sake of sincerity and sincere advice for Allah, His Book, His Messenger and the people of Islam. And He made it an inheritance by which the party of Allah’s Messenger and those allied to his Sunnah should be distinguished from the party of innovation and its helpers. And there occurs in a report whose isnad (chain of narration) escapes me at the moment:
“There is a pious servant who stands in the way of every innovation plotted against Islam, such that he speaks out making its signs clear.” So take the benefit of those gatherings and place reliance upon Allah, since mercy descends upon them.
We ask Allah that he makes us from them, and joins us with them, and that He makes us their later-followers, just as He has made them predecessors for us through His grace and beneficence.”
Tahdhīb Sunan Abū Dāwūd (7/61-62)