As-Salaam alaikum,
Ayat 38 of Surat Baqra of the Holy Qur'an (2:38) reads:--

"We said: Get ye down all from here; and if, as is sure, there comes
to you Guidance from Me, whosoever follows My Guidance, on them
shall be no fear, nor shall they grieve."

This is an address to Adam (alaihis-salaam) when he was sent to earth from Heaven along with his wife, Ummina Hawwa'u (Eve). Allah Ta'ala sent them His Guidance after sending them to earth... dunya...

Wherever there are children of Adam, there must be guidance there or else there will be no justice on earth. That guidance is meant to:--

(a) Show the right way... the good way to follow for peace and salvation.

(b) Indicate the bad way and instruction to not follow it.

All Prophets came on this guidance to purify us and show us the right way.