Yeah. Right. So about the question why so many messengers were sent and so many religions.
Abraham was the first one, he believed God is 1,Allah. He began to preach people to abandon idolworship and come to ur creator. Many started to learn, Islam was spreading. Time past and people took to worship materials, creation and not the creator. Then time came that Almighty Allah had to send another messenger to guide people to light again. Moses, Jesus (peace b upon them) were all messengers. They taught people Allah, God is one. There is not a single worse in Bible where u find Jesus(pbuh) saying to worship himself. He used to pray to Allah, and Allah would make miracles happen. But people began worshipping him. Cristianity was born. Allah has no relations, parent,kids,etc, Nor was Jesus(pbuh) his son ,but just a messenger.
To eradicate this wrong belief Allah sent the final messenger Muhammad (pbuh). He is the dearest to Allah,and the prince of all messengers, so his name is included in the awwal (first) kalima. He was the messenger sent for us.
Each messenger was sent for people of their times. Muhammad(pbuh) was sent for us. His arrival is mentioned in various religious scriptures
Islam is the true religion