The Purpose of Human Messengers

قُل لَّوْ كَانَ فِى ٱلْأَرْضِ مَلَـٰٓئِكَةٌ يَمْشُونَ مُطْمَئِنِّينَ لَنَزَّلْنَا عَلَيْهِم مِّنَ ٱلسَّمَآءِ مَلَكًا رَّسُولًا

Say, "If there were upon the earth angels walking securely, We would have sent down to them from the heaven an angel [as a] messenger."