Why did God create other religions, such as paganism, Judaism, and Christianity, given that Islam is the true religion? And why did the call begin with our master Abraham (peace be upon him) and not with our master Muhammad (peace be upon him)?

Islam, in its general sense, encompasses all divine laws brought by messengers such as Noah, Moses, Jesus, and Abraham, peace be upon them. However, in its specific sense, it refers exclusively to what was revealed to Prophet Muhammad, peace and blessings be upon him. Thus, whoever follows him is a Muslim, and whoever opposes him is not.

As for people deviating from Islam, it is part of Allah's will and wisdom. Allah created people diverse as a test for them. Among the wisdom behind this are: fulfilling Allah's promise to fill Hell, testing people by one another, and establishing jihad, enjoining good, and forbidding evil.

The call to Allah did not begin with Abraham, peace be upon him; rather, it commenced with humanity's deviation. Many messengers were sent before Abraham, such as Noah, Idris, Hud, and Salih. The conclusion of prophethood with Muhammad, peace and blessings be upon him, is because he was sent to all of mankind and jinn, and his law abrogates and completes all previous laws.