Because to them, Jesus is a minor prophet.
Because to them, Muhammed is the greater prophet.
Because to them, there is no such thing as “redemptive economy.”
I minored in upper level (junior and senior year level) Comparative Religion in college and so learned something about Islam. Among the things I learned is that Islam is the third religion (in addition to Judaism, of course, and Christianity) which includes the Hebrew Torah as part of their holy scriptures.
“Oddly” enough, they too revere Jesus’ mother (Mary) as a VERY holy woman.
Of course, the Q’uran is their main holy scripture.
For your convenience, I did a quick search on Google for “Islam.” Got this page.
islamworld.net/
That which you have been given is but a fleeting comfort of this life. Better and more enduring is that which Allah has for those who believe and put their trust in Him; who avoid gross sins and indecencies and, when angered, are willing to forgive; who obey their Lord, attend to their prayers, and conduct their affairs by mutual consent; who bestow in alms a part of that which We have given them and, when oppressed, seek to redress their wrongs. [Al-Qur’an, Sura: 42 (Ash-Shura), Ayat: 36-39]
Here’s a piece at that site that talks about “Forgiveness for All Previous Sins”
islam-guide.com/frm-ch2-4.htm