Indeed calling to Allaah was the mission of all the Messengers and their followers, in order to bring the people out from darkness and into the light, from unbelief (kufr) to true Faith (Eemaan), from Shirk to Tawheed, and from the Fire to Paradise.
Article includes the Tafseer of Soorah an-Nahl (16): Aayah 36 and Sooratul-Mu`minoon Aayah 117 by Shaikh Abdur Rahmaan as-Sad'ee (May Allaah have mercy on him).