A true "Sikh" is one who believes in Gurbani wholeheartedly, They also believe Guru Nanak Dev Ji is the only ship that can save you in Kalyug. A true Muslim believes in the Quran and Muhammad wholeheartedly. Similar concepts for a Christian, so tell me how Guru Nanak Dev Ji, Muhammad and Jesus are all on the same level. If only Guru Nanak Dev Ji can save someone in kalyug these figures can't do anything. So uhm no, its impossible to be both.
Mool Mantar says "Gur prasad", with the Grace of the GURU. So tell me is Muhammad a Guru now? The only Guru who's existed throughout the ages and who exists for anyone in Kalyug is Guru Nanak Dev Ji. Rather than repeating the same trash again and again and again I thought it would be smart to ask you a straightforward question but it seems that has either exploded your mind or (judging by the fact you can't seem to formulate your thoughts into 1 post) you just wish to talk out of your rear end all the time. I'll ask you again.
A Muslim who proclaims Muhammad is the only way to God. How can he also proclaim that Gurbani is a viable Option. The very core of any muslim is the fact that they all recite that Muhammad is the only way to God. SO tell me how someone can say 2 polar opposites and also be both. How can someone call something a lie and the truth at the same time. Gurbani also states that the Quran, Vedas etc are all incomplete, How can someone sit there and say that but also say "the Quran is perfect" . Yeah no. Nice try.