All Abrahamic religions are based on identical humanistic values. As I said you’d easily find all the 10 commandments in Quran too. And I am not saying it as a Muslim apologist which I am anything but. You can’t change facts.
Is it a humanistic value to kill those that leave the religion? https://www.theguardian.com/global/2015/may/17/losing-their-religion-british-ex-muslims-non-believers-hidden-crisis-faith https://time.com/4534504/bangladesh-atheist-blogger-murder-arrest-nazimuddin-samad/
In my view the answer is no, and I assume that the Russian Orthodox Church has the same opinion.
If that is the case then the Orthodox Christianity and Islam are NOT based on identical humanistic values. QED.
Furthermore, the Quran has borrowed a lot of text from the Bible see http://www.freerepublic.com/focus/f-news/1277705/posts and the Bible has borrowed from the Hammurabi Code https://avalon.law.yale.edu/ancient/hamframe.asp
Ths means that there are a lot of common ideas in the texts.