The purpose and authority of angels

مَا نُنَزِّلُ ٱلْمَلَـٰٓئِكَةَ إِلَّا بِٱلْحَقِّ وَمَا كَانُوٓا۟ إِذًا مُّنظَرِينَ

We do not send down the angels except with truth; and they [i.e., the disbelievers] would not then be reprieved.