Asallam alykum warahmatullaahi wabarakatuh.
Allaah subhana wata ala says in sura An Nahl
16:43 Wama arsalna min qablika illa rijalan noohee ilayhim faisaloo ahla alththikri in kuntum la taAAlamoona
16:43 And We sent not (as Our Messengers) before you (O Muhammad Sallallahu alyi Wasalam) any but men, whom We inspired, (to preach and invite mankind to believe in the Oneness of Allah).
So ask of those who know the Scripture if you know not.
I would recommand you to sumbit your question to these adres inshAllaah biidhinillaah so you will get the most accurate answer for your friends situation inshAllaah. Allaah knows best.
You would also log to this site to directly submit your question,
http://understand-islam.net/
or use the mail addy to mail,
info@understand-islam.net
Wasallam alykum