Allah سبحانه الله و تعالى mentions in his noble book, regarding those who put the believers to trials(by oppressing them, harming them, etc.):
(translation of meaning by Muhsin Khan): Verily, those who put into trial the believing men and believing women (by torturing them and burning them), and then do not turn in repentance, (to Allah), will have the torment of Hell, and they will have the punishment of the burning Fire. [Al Buruj:10]
Imam Ibn Katheer mentions in his tafseer(9/433, darussalaam print) that Imam Al Hasan al Basri said, “Look at this generosity and kindness! These people killed Allah’s awliya’ and he still invites them to make tawbah(repentance) and istigfaar(seek forgivness)”.