وَنَبِّئْهُمْ عَنْ ضَيْفِ إِبْرَاهِيمَ إِذْ دَخَلُوا عَلَيْهِ فَقَالُوا سَلَامًا ... [1]
“And inform them of the guests of Ibrahim: when they (i.e. angels) entered upon him, they said, Peace. He said: Surely we are afraid of you. The angels said: Be not afraid, surely we give the good news of a boy, possessing knowledge. He said: Do you give me good news of a son when old age has come upon me? – Of what then do you give me good news! The angels said: We give you good news with truth, therefore be not of the despairing.”
From verses like these and according to the authentic Islamic narrations, it is clear that if angels accompanied by God’s Mercy did not protect man against calamities, life would not be safe from anxiety and the agents of destruction.
source : The Book: Diar Aashiqan by prof, Hussain Ansarian