Az-Zuhd (Non-Materialism)
A Muslim should be Zaahid toward this world and what is in it. Zuhd means to turn away from inclination toward something and preoccupation with it out of holding it in low regard. To be zaahid toward something is to free oneself of desire for it.
In Islam, the word zuhd is used to mean to turn away from preoccupation with this world and prefer focus on the hereafter. Put another way: leaving the ease of this world seeking the ease of the hereafter. One who goes this way trusts fully in what is with Allah and not what is in his hand and fills his heart with reliance on Allah Most High. This is the only way to felicity in this life and in the hereafter, as the Prophet (sas) said:
"How amazing is the affair of the believer. Everything that happens to him is good. If good things come to him, he is grateful and that is good for him. If he suffers some adversity, he is patient and that is good for him. So, whatever happens to him is good. And this is for no one but the believer." (...or, as he said(sas))
Zuhd to a Muslim is a question of focus and intention, not avoiding the "things" of this world. There is no reward for a Muslim to be intentionally poor. In fact, one who chooses this road loses the chance for paying more zakat and giving more sadaqa. The things of this life can be a MEANS to the reward of the hereafter. Running away from the things of this world as such - or "asceticism" is an innovation which the Christians brought about in their deen. Allah said:
{...Wa qaffainaa ti 'isa ibni Maryam wa aatainaahu al-injeela wa ja'alnaa fiy quloobi alladhina ittaba'oohu ra'fatan wa rahmatan wa rahbaaniyatan ibtada'oohaa maa katabnaahaa 'alaihim illa ibtaghaa'a ridhwaani Allahi fa maa ra'auhaa haqqa ri'aayitahaa...}
{...And we followed them with Isa the son of Maryam and we gave him the Injeel and we placed in the hearts of those who followed him compassion and mercy and asceticism they innovated it we did not prescribe it for them, only seeking the pleasure of Allah, but they did not maintain that is it should be maintained...} Al-Hadeed:27
Notice that not only was their "sacrifice" of asceticism something not called for by Allah but at the same time, Allah mentions that in fact they did not take proper care of seeking the pleasure of Allah. This is the sunnah of Allah's creation: those who "overdo" in any area of their practice are negligent in some other area. Deviating from the deen as ordained by Allah never brings any good, even when it appears to be "more".
In fact, part of Allah's promise is that focussing on the hereafter will bring this world and what is in it into submission. The Prophet (sas) said:
"Whoever started his day with his attention focussed on this life may get it, but will have no share in the hereafter. Whoever started his day focussed on the hereafter will get his share thereof and this life will come to him in submission." (...or, as he said (sas))
Our portions of this life have been assigned. We cannot cause them any increase or decrease. Everything which we get in this life is mere provision for our short stay in this life. What we do with it (our deeds) determines our state in the pemanence of the hereafter. Allah said:
{Al-maalu wa al-banoona zeenatu al-hayaati ad-dunyaa wa al-baaqiyaatu as-saalihaatu khairun 'inda rabbika thawaaban wa khairun amalan.}
{Wealth and sons are the ornamention of this life and the enduring, the good deeds are better with your Lord in reward and are better objects of hope.} Al-Kahf:46
{Allahu yabsutu ar-rizqa liman yashaa'u wa yaqdiru wa farihoo bil-hayaati ad-dunyaa wa maa al-hayaatu ad-dunyaa fiy al-aakhirati illa mataa'un.}
{Allah expands the wealth of whomever He wishes and restricts. And they rejoice with the life of this world but the life of this world compared to the hereafter is nothing but some provisions.} Ar-Ra'd:26
Obsession with the things of this life stands in opposition to tawakkul (reliance) of Allah. Those who know reliance on Allah will not be obsessed with material things. Allah said:
{Fa maa ooteetum min shai'in fa mataa'u al-hayaati ad-dunyaa wa maa 'inda Allahi khairun wa abqaa lilladhina aamanoo wa 'alaa rabbihim yatakkaloona.}
{So whatever you have been given of material things is provision for the life of this world and that which is with Allah is better for those who believe and upon their Lord place their reliance.} Ash-Shooraa:36
Those who rely on Allah and do not become obsessed with material things will have a higher station and a greater respect not only with Allah, but with the people of this world. It was said to the Prophet (sas):
..."Izhad fiy ad-dunyaa yuhibbuka Allahu, wazhad fimaa 'inda an-naasi yuhibbuka an-naasi."
O, Messenger of Allah, guide me to an action which if I do it Allah will love me and the people will love me. He (sas) said: "Be zaahid toward the things of this life and Allah will love you and be zaahid toward what the people possess and the people will love you." Ibn Majah
One of the early generations said:
"The one who is zaahid in this life does not condemn this world nor does he praise it. He does not rejoice when it comes to him nor grieve when it leaves him. He does not look at it."