Salawat (durud), Sending Salam to Prophet Muhammad peace be upon him during Salat in Tashahhud

My question is about the Tashahhud in the five time prayers, "ATTAHIYAATU LILLAHI VAS SALAVAATU VAT TAYYABAATU ; ASSALAMU ALAIKA AYYUHAN NABIYU VA RAHMATULLAHI VA BARKATUHU", My understanding is that these words "AYYUHAN NABIYU " means that you are directly referring to Prophet Muhammad peace be upon him as if he is MUKHATEB (listener), in other words, calling someone present.Now if this is true and my understanding is correct then I am bit confused, Because Prophet Muhammad peace be upon him is not alive and giving the SEFAT or attribute GOD LIKE adjective being always alive is KUFR and biddah . Like the believe of the religion sect called Barelvi that they believe that Muhammad peace be upon him can hear them and they always send durud like "WA SALATU WASALAM YA RASUL ALLAH" which most scholars consider as Biddah.