lmam Ghazali has reported from our master Hasan Basri (Allah have mercy on them) a narrative that Satan said:

“I presented sinful deeds in an attactive form to the Muslims, but they nullified my efforts through repentance (istighfar). Then I presented before them vices in the garb of virtues, thus leaving no initiative for repentance.”

Instances of such vices are self-made innovations (bidah) in religious practices.

Vitues of Zikr, page 133