Hisgot:Islam
Monotestika? usba
(1) "usa ka monotestikang Abrahamikong relihiyon"
Perhaps "monoteistika" would be a better form to borrow the English word "monotheistic". Alternatively, a Spanish-derived form (used in the Spanish article on Islam) is "monoteista".
I think the more fundamental issue is: would the target readership of this article even understand the loanword in any of these forms? I would appreciate a pointer to any past discussion of who is the target audience, I have not been active on this wikipedia (I speak Cebuano as a second language, I am not fluent enough to write in it.) I would hope that one of the major audiences is school children who are native speakers of Cebuano, and would have a hard time understanding the English article. I think that audience would be better served if there was a phrase explaining what was meant by the term "monotheistic", rather than a new loanword (or in addition to the loanword, which could appear later in the text).
A model could be taken from the Simple English article on Islam:
(2) They believe in only one God, that God is called Allah, which is the Arabic phrase for "the (only) God".
Just delete the word "monotestikang" from (1) and add a translation of (2) after it.