If a person offers only Furd(Obligatory)prayer and leaves sunnat and nafal i.e He only prays 4 furz of Zohr prayer then Is he 'SINFULL"....or not

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

First of all, we would like to say that a Muslim should not neglect supererogatory prayers, especially the Rawaatib Sunnah prayers [i.e. confirmed or unconfirmed supererogatory prayers that are performed either before or after the obligatory prayers] because they are among the greatest actions of worship by which one gets closer to Allaah after the obligatory prayers.

Therefore, whoever abandons the supererogatory prayers has indeed missed a great reward; since by regularly observing the Sunan (plural of Sunnah) and the supererogatory prayers, one gets closer to Allaah as these acts are an access door towards gaining the love of Allaah. Allaah says in a Qudsi Hadeeth: “My servant continues to draw near to Me with supererogatory acts of worship until I love him.” [Al-Bukhari]

Hence, if Allaah enables a person to do that, it is a sign that Allaah loves him and is pleased with him and that He has granted him success.

If a person abandons the good deeds that he used to do without a sound reason, then this is dispraised in general even if that was a supererogatory prayer but he does not become sinful unless he abandons obligatory prayers.

Nonetheless, abandoning the supererogatory prayers may lead to neglecting the obligatory prayers as clarified by the scholars. Therefore, a Muslim should not abandon the supererogatory prayers especially the Rawaatib Sunnah prayers.

As regards whether or not a person who abandons the supererogatory prayers is sinful, then there is a difference of opinion among the scholars on this issue. Some of them are of the view that he is not sinful as Talha Ibn ‘Ubaydullaah said: “A man came to the Prophet asking him about Islam, the Prophet said: ''You have to offer five obligatory prayers in a day and a night [24 hours]." The man asked: "Is there any obligatory prayers other than these that I have to perform?" The Prophet replied: "No, unless you wish to perform supererogatory prayers." The Prophet then added, "You have to fast the month of Ramadan." The man said: "Am I obliged to fast any other days besides these?" The Prophet said: ''No, unless you wish to observe optional fasting." Then the Prophet mentioned to this man obligatory Zakah. The man asked, "Do I have to give anything besides it?" The Prophet said: "No, unless you wish to give in charity." So, the man departed saying, "I swear by Allaah I will neither do more nor less than that." The Prophet said: "If he is saying the truth, he will be successful (i.e. he will be granted Paradise)." [Maalik, Al-Bukhari and Muslim]

Another wording of Al-Bukhari is: “By Him Who honored you, I will neither volunteer anything nor decrease what Allaah has enjoined on me.”

Al-Nawawi said while commenting on this Hadeeth in his interpretation of Saheeh Muslim: “It is probable that he meant that he did not want to pray the supererogatory prayers while not falling short in performing the obligatory prayers, and such a person is successful without doubt, even though persisting in abandoning the Sunnah prayers is something dispraised, and it necessitates the rejection of his testimony but he is not disobedient, rather he is successful.”

Besides, Badr Ad-Deen Al-Ayni said the same thing while commenting on the Hadeeth reported by Imaam Al-Bukhari: “It is probable that he meant that he would not pray the supererogatory prayers while observing all the obligatory prayers. Such a person is successful without doubt even though his persistence in abandoning the supererogatory prayers is something dispraised.”

On the other hand, some scholars of the Salaf (righteous predecessors) are of the view that the person who continuously neglects the Sunnah prayers is sinful and that the Hadeeth quoted above was before the supererogatory prayers were legislated. Ibn Rajab said while interpreting the chapter of Saheeh Al-Bukhari about abandoning the night prayer: “Some scholars said that what is meant is that if a person continuously abandons the night prayer or abandons it so often, his testimony should be rejected because of that as this is being negligent about the confirmed Sunan. This ruling applies to all the Rawaatib Sunan; this is the view of the prominent scholars in our School (the Hanbali School).

“However, some other scholars said: “The Hadeeth proves that if one abandons the confirmed desirable prayers, he is sinful but his sin is lesser than the sin of abandoning the obligatory prayers. Besides, Al-Qaadhi Abu Ya’la said: “If a person continuously abandons the Rawaatib Sunnah prayers, he is sinful. This is the view of Is-haaq Ibn Raahawayh who said in his book entitled “Kitaab Al-Jaami’”: “No one is punished for abandoning any Nafl (supererogatory) prayer, as the Prophet had legislated the Sunnah (supererogatory) acts of worship other than the obligatory acts of worship which Allaah enjoined on us, so it is not permissible for a Muslim to be neglectful about the Sunan which the Prophet had set for us, such as the prayers of ‘Eed Al-Fitr and ‘Eed Al-Adhha, the Witr prayer, and slaughtering the sacrifice of ‘Eed Al-Adhha, and other similar acts of worship. If one abandons them out of negligence, he will be punished unless Allaah forgives him, and I fear that (the punishment) when abandoning the two Sunnah rak'ahs of Fajr and the two Sunnah Rak’ahs of Maghrib as Allaah described them and urged us to perform them; Allaah Says (what means): {And [in part] of the night exalt Him and after prostration [i.e. prayer].} [Quran 50:40]

Allaah also Says (what means): {And in a part of the night exalt Him and after [the setting of] the stars.} [Quran 52:49] Moreover, Sa’eed Ibn Jubayr said: “I fear that I will not be forgiven if I abandon the two Sunnah Rak'ahs of Maghrib.” [End quote]

To conclude, you should know that there is a difference of opinion among the scholars in considering the person who abandons the Rawaatib Sunnah prayers as sinful, so one should not neglect them.

Allaah Knows best.