Secondly on speaking with many Muslims, many have no respect for the previous revelations; most haven't even read the Bible, let alone any other religious texts.
Then when asked why they don't, they will say they're corrupted, and some of the things within it they personally don't like, so they think it is rubbish....
I've only ever seen one Muslim based on what i read within the Quran, who was a doctor of theology on the Islam channel, he could clearly explain where many religions that some might think are polytheistic, are not, and it is a misunderstanding of their texts.
So just to clarify 'to believe in the previous revelations', you have to know them, which means reading, and studying them....
To be able to share 'where the fake religions are in error', you need to spend time questioning where the errors are, and again know the text....
Thus imagine if Muslims had done this throughout the history of Islam, the world would already be at peace, and the whole world would be following Islam, as it would be one religion with all the books as One.....
Instead due to human ego, we've got a world on the brink of collapse.