Alif Laam Raa. A book which We have sent down to you so that, by the permission of their Fosterer, you may bring out mankind from the darkness (and lead them) towards the light, towards the path of the Mighty, the Praised.
The purpose of sending messages and messengers by Allah (SWT) was to bring mankind out of the darkness of disbelief towards the light of belief so as to save them from hell and lead them towards paradise.