"For those who may be unaware, in Yiddishkeit, Satan is a tool of Hashem. As the Gemorah in Bava Basra says, Satan, the Yetzer Hara, and the Malach HaMoves are the same entity, and that Satan does his actions 'Leshem Shomayim' (or he at least claims to do so)." (source)

"We had such difficulties raising money for that clinic—as if the Satan were trying to screw things up." (Glinert)