your answer looks as if it was written by ISIS themselves! did you just copy and paste it from one of their websites?
Any proper scholar of Islamic Legal Jurisprudence [fiqh] will know that cherry-picking verses from the Recitation (of God) [l-Qur’an] and examples from the Prophetic-Narrations [l-hadith] out of their proper context is an invalid way to deduce legal rulings - and this type of thing is only done by ISIS or other enemies of Islam who purposely distort the truth to suit their own warped views and push them onto others.
If this article were how muslim scholars thought, then ISIS would not be limited to the extremist sects of the religion - the Khawarij - rather, it would have been how the main body of Muslims behaved throughout history till this day. Yet we find that ISIS type groups have only emerged in the past century and that for 10s of centuries before them the main body of muslims have lived in peace with other ethnic and religious groups around the world.
Any serious and sincere person can verify what I have said by reading history from an unbiased viewpoint, or alternatively reading into the teachings of Islam as taught by well informed scholars of the main body of the religion - not by extremists and those who lack understanding of the religion.
If you haven’t the time to read into history, then consider this: how is it that non-muslim groups like Yezidis and Druze and synagogues and churches could all be found in muslim dominated lands after all these centuries (prior to the rise of ISIS)? surely, they would have been killed off and destroyed long ago if islam's core teachings were just like ISIS
Similarly, if you haven't access to a proper Islamic scholar - then I recommend you read the book “Refuting ISIS” - written by a certified contemporary scholar of Islam (Shaykh Muhammad al-Yaqoubi). He provides the “proofs” which ISIS use to justify their crimes - and then provides the correct contexts and proofs to show how they are acting against Islamic Legal Jurisprudence.
an example extract
“ISIS uses the story of ˓Alī as a proof, as it is narrated that he burned someone. However, the story does not provide any proof to the permissibility of burning people for the following reasons. First, Ibn ˓Abbās, cousin of ˓Alī, opposed him and declared that it was wrong. Second, Imam al-Bukhārī narrated this story to caution the reader that it is not valid, as he narrated the counter-proofs. His job was to compile every text related to the subject, and the job of the doctors of law was to establish what is valid and what is not. Third, ˓Alī himself agreed with his cousin Ibn ˓Abbās that this is forbidden, as narrated by al-Tirmidhī.”