There are religions whose god is not the God of the Christians. Many are worshipers of idols but they claim they believe in God.
There religions that do not accept the lordship of Jesus christ. Such religion can not believe in God because whoever denies the son has denied the father.
Many religions believe in different doctrines, but the only one and true God of the bible teaches us only one doctrine. He doesn't have diffrent doctrines.
He is the God who spoke to moses, Abraham, Isaac and Jacob, Noah and all the fore fathers of faith.
There are no many gods, there is only one God and he is the one who reveals himself through the holy scriptures, 'The bible'
Galatians 4:8
But then, indeed, when you did not know God, you served those which by nature are not gods.*
When people are ignorant about the true God, they will fall into the hands of false gods.
But whoever submits himself to the ordinances of the true God will experience salvation.
This is the post of brother Eli if you want to make a comment video ;