The ruling on leaving many sunnahs because they are not obligatory

Question:
Many people leave much of the guidance of the Messenger of Allah (peace and blessings be upon him) on the grounds that it is a sunnah, for which its doer is rewarded and its leaver is not punished. Do these people have any truth in what they say?

Answer:
This requires a detailed explanation:
Whatever is established by the evidence of the Shari'ah as not being obligatory, there is no blame on the one who leaves it, such as the voluntary prayers: the sunnah of Dhuha, the sunnah of Dhuhr, the sunnah of 'Asr, the sunnah of Maghrib, the sunnah of 'Isha, and Witr. These are voluntary prayers; if one leaves them, he owes nothing, and if one is consistent in performing them, he is better and more complete. Consistency in them is a cause for preserving the obligatory acts, a cause for making up any deficiency that may occur in the obligatory acts, and a cause for success in all of his deeds. And if one leaves some of them, there is no blame on him.
But the one who leaves the obligatory acts is the one who is subject to objection, and the place of error, negligence, and sin.
As for the voluntary acts, their matter is broader, and praise be to Allah. But one should take care of them and be consistent in performing them, because of the great good in them, the many good deeds, and the completion of the obligatory acts. Also, by them, along with striving in good deeds, one becomes among those who are ahead.
One who limits himself to the obligatory acts is only among the righteous, the people of the right hand. But one who expands in good deeds, expands in righteous works, takes on the voluntary acts, stays away from disliked things, and strives; by this, he becomes among those who are ahead and brought near, and they are of a higher rank, with a greater reward and recompense.