Re: How does one know?
Yes, I am referring to the practice of the majority who combine Quran, sunnah and hadith as part of their religion.
first prove that Quran , sunnah and hadith do not have same source so not a part of religion
in many places in quran , it is ordered to muslim , follow Muhammad
if you donot act on sunnah /hadees ie you don't like to follow Muhammad that it means you are denying Quran and not following quran
all the scholars of islam have told that who ever say , that i follow quran but not sunnah or hadees is the biggest liar
there can be difference on authenticity of any hadees but it doesn't mean that reject every hadees and sunnah