May peace be with you.
The
immediate audience to whom the Quran primarily attempted to convince of its Divine origins were the Desert Arabs of the c. 7th century. The Quran provided narratives, signs and wider arguments that they could
readily relate with and thereby fully understand the full remit of its arguments.
It also related stories in the main with which the Arab audience would have been familiar with, again with a view to convince them of the Scripture's Divine origins.
The Quran
was not revealed as a history or a science Book, nor did it intend to provide narratives which would have made little sense to the immediate Arab audience.
This is why you do not find direct, explicit references to prehistoric creatures roaming the planet, nor do you find specific references to all the communities on planet Earth to whom messengers were sent. Arguably, what you do find is relevant information which would have been pertinent for the contemporaries of the Prophet's ministry.
Lastly, there are many obscene materials in Sahih Books but in response from Mainstream groups we hear that how will we perform Nikah, setup Zakat, bury our deads or perform prayers etc.....if books of Hadith and possibly 4 Imams are not around?
I appreciate what I understand is your underlying sentiment, i.e. how can one use a source for religious authority when it contains evident weaknesses and incredulous narratives such as those found in the Islamic secondary sources? or indeed, how can a
fallible source such as Ahadith ever explain a Divine
infallible source such as the Quran?
Overarching guidance is clearly provided in the Quran for all the matters you have raised. What the mainstream groups may be seeking are justifications for their ever complexities and finer details that have now become (without warrant) prescribed in the name of religion.
Following a tradition as best practice is one thing, claiming that is has
Divine religious authority is another.
With respect, the burden of proof is with those that make such claims to provide clear
unequivocal evidence from the Quran where God informs believers that such fine details are prescribed as
‘religious authority’ and therefore need to be sought from
other sources such as books of Ahadith.
The connection that is usually made to validate such claims is that the Quran informs believers to
‘obey the messenger’ [1] and thus all that has been written about him in his name by
late compilers often centuries removed from his ministry is thus binding. Such an assertion from a Quranic perspective is extremely moot (i.e. debateable).
Please see references below where I have discussed the subject matters you have raised from my humble understanding of a Quranic perspective.
I hope this helps, God willing.
Joseph.
REFERENCES:[1] OBEY ALLAH (GOD) AND THE MESSENGERhttp://quransmessage.com/articles/obey%20allah%20and%20the%20messenger%20FM3.htm[2] NIKAAH - THE CONTRACT OF MARRIAGEhttp://quransmessage.com/articles/nikaah%20FM3.htm[3] WHAT IS THE CONCEPT OF ZAKAT FROM THE QURAN?http://quransmessage.com/articles/zakah%20FM3.htm[4] PREPARING THE DEAD BODY FOR BURIAL AND THE QURAN'S PERSPECTIVEhttp://quransmessage.com/articles/preparing%20the%20dead%20body%20for%20burial%20and%20the%20quran's%20perspective%20FM3.htm[5] HOW CAN WE LEARN PRAYER IF WE DON'T HAVE HADITH TO TEACH US?http://quransmessage.com/articles/prayer%20without%20hadith%20FM3.htm