Originally Posted by crimsontide06
Those words Islam and Muslim are Arabic words hence that's why they may not have existed in previous scriptures as previous scriptures were in Hebrew and Aramaic.
There is a difference of opinion in Islam as to what the previous religions were called, one group of scholars maintain that they weren't called Islam and that only our religion is named that
It doesn't really matter what the previous religions were called as what we share with their original revelations is their beliefs which were always the same. They only differed in practices:
Though the Sacred Law of the Prophet (Allah bless him and give him peace) superseded all previously valid religious laws, it was identical with them in beliefs, such as tawhid or "oneness of God", and so on, a fact that the Prophet (Allah bless him and give him peace) emphasized by saying, "Let none of you say I am superior to [the prophet] Jonah," (Bukhari, 4.193: 3412), for the illumination of Jonah's tawhid (upon him be peace)--under the darkness of the storm, the darkness of the sea, and the darkness of the belly of the fish--was not less than the illumination of the Prophet's tawhid at the zenith of his success as the spiritual leader of all Arabia (Allah bless him and give him peace). The light of their message was one, in which sense the Qur'an says, "We do not differentiate between any of His messengers" (Qur'an 2:285), showing that previous religions were the same in beliefs, and though differing in provisions of works, and now abrogated by the final religion, were valid in their own times.