People who do not accept Hadith or Sunnah have following arguments to make.
…The duty of the Prophet (may the peace and mercy of Allah be upon him) was to convey the message. Nothing more was required of him.
…..Some go farther and say OK He (PBUH) had to convey the message, set an example by his actions and explain it as well “but all that was for a specific time period”. After his departure from the physical world Qur’an is enough.
Then a question arises “ is there a need for the Prophet (PBUH) in Islam”. Let us think about it for a moment “there is no need for the Hadith” If there is no need for the Hadith then why is the Prophet there. One might argue we do need Sunnah. Perhaps we do but another problem arises. The only recorded Sunnah is in the books of Ahadith. To further elaborate, each action (Sunnah) of the Prophet (PBUH) is not only explained in the books of Ahadith but the details of that action (Sunnah) are also given. By the way if you read any book of Hadith, it is safe to say that every one of the Ahadith are actions of the Prophet (PBUH) because he was not a person of mare words he acted upon something and only then he told the companions to do as he did, hence the Hadith. If we take record of Ahadith out of the religion, we take Sunnah and finally the need for the Prophet out of the religion. No Hadith, no Sunnah and no need for the Prophet, and one claims to believe that Quran is word of Allah. How could such claimer prove the divinity of Quran or if he dismisses the only witness that is the Prophet (PBUH); the only person Allah Jalla-Shano-Hoo spoke with. If a lawyer is not present to defend the case the case is dismissed. Applying the same analogy if the Prophet is not needed then the claim that Quran is a divine word is dismissed. Hmmm
If we base Islam only on the Holy Quran, then there is virtually no need for the Prophet (May the peace and mercy of Allah be upon him). Allah Jalashanoho could have sent the book through angels and be done with it. Interesting notion!
There is another argument that “everyone can understand Quran as is and there is no need for interpretations or explanations from the Aahadith (and Sunnah). That is scholarly arrogance or perhaps utter ignorance in my humble opinion. Let us see how one becomes a scholar of Tafseer (interpretation and explanation of Quran). Students of the Tafaseer-e-Quran are taught meaning of every verse, then every verse is back tracked to the situation it was sent in. Finally the words used in a verse are cross referenced with the meaning of those words in use at that specific time which would be the time of the Prophet (PBUH) himself. Possessing complete knowledge of every situation for every verse and having in depth knowledge of the Historical Arabic language as well as the early Tafaseer only then one could understand the depth and breadth of the Holy Quran. If we take Hadith out of this equation we are left in utter darkness.
Let us come back to the basic questions, is there a need for the Prophet (PBUH) today and his Hadith and the Sunnah???
Let us see what Quran has to say about it.

And obey Allah and the messenger, that ye may find mercy" (Qur'an 3:132).

This seems very straight forward, by obeying Allah we could say it means his commandments in the Holy Quran, but we took Hadith and the Sunnah out so how could we fulfill the second part that says “And the messenger (PBUH).” If you notice Quran here does not say read Holy Quran and interpret it yourself. It says Obey Allah (his word that is Quran) and obey the Prophet (PBUH). How could one obey the Prophet (PBUH) if he denies what the Prophet (PBUH) said (Hadith) or did (Sunnah).

And whatsoever the Messenger allows you to do, do it. And whatsoever he forbids, abstain (from it.)" (Qur'an 59:7).

Here Allah Jala Shanuho went farther to dissipate the doubt. He did not mention Himself or said “My words (Holy Quran)”, he directed all of us to His Messenger (PBUH). Whatever he allows you to do, do it. Could we say “but Allah Paak we do not believe in the Hadith and we also do not believe that Prophet could communicate with us, how could we know what he allows us to do and forbids us not to do. Hmmm.
How could one do anything that the messenger said without believing in his Sunnah or Hadith. Another Hmmmmm and a long one at that LOL. One might say Quran is talking about itself. Well if that would have been the case Allah would have said obey Allah, his word, or Qur’an. But Allah mentions the messenger, which clearly means Sunnah and the Hadith, I wanted to go farther but that could give some of us indigestion.

"obey Allah and obey the Messenger... If you should quarrel over anything refer it to Allah and the Messenger" (4:59)
Here we go again Quran enforcing it again, Obey not only Allah (His word Quran) but also the Prophet (PBUH).

"In Allah's messenger you have a fine model for anyone whose hope is in Allah and the Last Day" (33:21).

But we do not believe in Hadith how could we find this model. Hmmmm It could not be more clearer than this. Allah himself has put a condition, if you want his mercy on the last day then take his messenger as the model. If one does not know how the messenger of Allah spent his life, how could one discover about this model. We could go on and on……

“O you who believe Obey Allah AND Obey the Messenger (PBUH).4:59
The one who obeys Allah AND his Rasool …….. 4:69
And Obey Allah AND His Rasool (PBUH) 5:92

I am not going to quote all the Ayaat but will provide a list
8:20, 9:33, 17:1, 17:105, 24:52, 24:56, 26:216, 33:21, 33:36, 33:57, 43:43, 45:18, 47:33, 53:2, 59:7, 62:2, 68:4.

Surprisingly enough the people who deny the importance of Hadith, if they decide to pray they pray two Rakah for Fujr, four for Zuhar, four for Asr, three for Maghrib so on and so forth. Someone should ask them “sir/madam the number of Rakah for any prayer, and a set time is not mentioned in the Holy Quran, why then you are praying the way the Prophet told us pray.

Quran does mention times for the obligatory prayers but in vague statements. It is the Prophet who showed us how to pray and when to pray.
For example.
Establish worship at the two ends of the day and some watches of night.(11:114)
Who is to define what times of two ends and when at night. Only the Prophet(PBUH) has the authority to do so, because he is guided by Allah Jallah Shanoho himself.

Here is another example.
Establish worship at the going down of the sun until the dark of night, and (the recital of) the Qur’an at dawn. Surely (the recital of) the Qur’an at dawn is ever witnessed. (17:78)
Now how do we know what time to pray what prayer from the late afternoon till the darkness of the night? Only the Prophet showed us how and when to pray Zuhar, Asr, Maghrib and Isha.

In Surah Taha Ayah 130 Allah Jalla ShanoHo has mentioned prayer times in similar fashion.

People who deny the importance of Hadith provide elaborative arguments and extract times from above mentioned Aayaat. I ask them on whose authority, did Allah Jallah-Shano-Ho told them. If the Sunnah and the Ahadith are not there, how could one find out how many Rakah to pray and at what exact timings.
Prayer is one of the most important obligatory acts in Islam yet following details about the prayer are not mentioned in Quran, only Sunnah sheds more light on these details.
1. Exact times and the time limit for a prayer. For example the time of Fajir prayer starts when the darkness of night is fading till you can see the sun light on the horizon.
2. Times when prayers are forbidden for example a short time when the sun is rising.
3. Requirements of the prayers, for example, Wadu (ablution), clean cloths and a clean place for prayer. So on and so forth.
Moving along let us look at the Wadu.
The ruling of the Wadu mentioned in Quran has four Faraid of the Wadu in following Ayah.
Allaah Jala Shanoho says: O Ye who believe! When ye prepare for prayer, wash your faces, and your hands (and arms) to the elbows; rub your heads (with water); and (wash) your feet to the ankles (Sorah Al-Maa'idah, 5:7)

These obligations (Faraid) are:
1. Wash your face
2. Wash your hands to elbow
3. Rub your head (masah) and
4. Wash your feet.
More details about ablution (Wadu) are mentioned only in the Hadith, for example,
1: saying Tasmiyah at the beginning,
2: putting water in your mouth to gargle,
3: putting water in your nose and cleaning it,
4: during masah cleaning your ears.
5: washing every part three times, using Miswaq etc are omitted from Quran.
If someone follows just the Holy Quran and ignores Ahadith then he should pray according to what Quran ordains. I have to say this to such followers, “good luck”.

To sum it all up, Allah Jallashanoho put it in the best way possible.
Whoever obeys the Messenger (PBUH), indeed obeys Allah; and whoever turns away, so We have not sent you (O’ Prophet) as a keeper over them. (4:80)
Now there is nothing clearer than that.

I read following Ayaah that got me thinking. Is the Prophet really gone and there is no spiritual connection of the believers with him…..

The Prophet (PBUH) is closer to the believers than their own selves (Nafs, one of the meaning of Nafs is source of life). (33:6)

Which believers Quran is talking about, the ones who were present with Him (PBUH), or believers of all the time to come. Even if it is said about the ones who were with him, how could he be close to all of them, closer than their own selves (Nafs).
Imam Bukhari (may the mercy of Allah be upon him) reported a Hadith from Sayyidna Abu Hurairah (RadiAllaho Anh) which says “There is no such believer for whom I am not the closest of all people in this world and in the world to come…..”. This translation was taken from English version of Ma’ariful Quran Volume 7 page 94, commentary on Surah Ahzab Aayah 6.

O’ here is another one.

“Even as We have sent to you a Messenger (PBUH) from among you, who recites to you Our revelations AND causes you to grow in purity {(U ZAKEE QUM) is referring to the Prophet (PBUH) not the Ayaat)}, and teaches you the Scripture and Wisdom (here again Hiqmah is referring back to the Prophet which means it comes from the Prophet not the Ayaat), and teaches you that which you knew not”. (2:151) Here is what Ma’Ariful Qur’an by Mufti Mohammad Shafi says in volume 1 on page 398 “Verse 51 “the new Prophet (Mohammad PBUH) is sent with the same attributes as specified by Sayyidna Ibraheem Aleyhis Salaam’s prayer namely: 1) He recites to them the verses of the Holy Qur’an ; 2) He teaches them the book and the wisdom; 3) He purifies them; 4) He teaches them things which his listeners did not know of, nor could they be found in the earlier divine books or through individual reason.

Now if we take Hadith and the Prophet out of Islam. The purity of Nufs ( Tazqiyah Nafs) knowledge of the Scripture and Wisdom is out of our lives. Allah did not say the words of the Prophet (PBUH) teach you Tazqiyah or give you wisdom, or my words give you Tazqiyah Nafs. He Jalah Shanaho said the Messenger himself gives you purity of your Nafs, the knowledge of the scripture and the Wisdom. Could it be just for His companions and there is no share for us the “later generations”. Hmmm.
Then the question arises, is Quran really Universal, for all the times, till the day of the judgment. If it is then there must a share of (U ZAKEE QUM) for all of us to come and perhaps the share of wisdom and knowledge as well. We need to contemplate upon this.

Disclaimer: I am not a Mufti have limited knowledge and limited understanding of the religion. All I have tried is, to the best of my knowledge proved evidence that supports a point of view. What course you take is not my responsibility. All mistakes are mine and all prays are for Allah and the respect is for those who are in HIS nearness especially HIS most beloved and best creation Prophet Mohammad may countless blessing be upon him, his kin, his companions, and all his followers.

JazakAllah Khairun. Very nice article MianGM.