On there being people who do this work
A command that a group should exist, not that everyone must.
وَلْتَكُن مِّنكُمْ أُمَّةٌ يَدْعُونَ إِلَى ٱلْخَيْرِ وَيَأْمُرُونَ بِٱلْمَعْرُوفِ وَيَنْهَوْنَ عَنِ ٱلْمُنكَرِ ۚ وَأُو۟لَـٰٓئِكَ هُمُ ٱلْمُفْلِحُونَ
Wa-l-takun minkum ummatun yadʿūna ila-l-khayri wa ya'murūna bi-l-maʿrūfi wa yanhawna ʿani-l-munkar…
“And let there be [arising] from you a nation inviting to [all that is] good, enjoining what is right and forbidding what is wrong,1 and those will be the successful.”
Source
The Qur'an · 3:104
Qur'an
- Qur'anic text in the Uthmani script via Quran.com; translation: Saheeh International