god does not forgive the sin of considering others equal to him but he may choose to forgive other sins. whoever believes in other gods besides him has indulged in a great sin.
إن الله لا يغفر أن يشرك به ويغفر ما دون ذلك لمن يشاء ومن يشرك بالله فقد افترى إثما عظيما