The Best Quality is to Have Trust in Allaah

As for the next part of the question, about the most valuable quality to aim for, then the answer to this is that the best prize is to have trust in Allaah, reliance upon Him of His sufficiency, and keeping a good opinion of Him, the latter being that if anyone is anxious regarding their sustenance then he should turn to the shelter of Allaah, as the Exalted said, from what is narrated by His Prophet, sallallaahu `alayhi wa sallam,
"O My servants, all of you are hungry except for those I have fed, so seek food of Me and I shall feed you. O My servants, all of you are naked except for those I have clothed, so seek clothing of Me and I shall clothe you." [Upon Aboo Dharr, related by Muslim, at-Tirmidhee, and Ahmad]
In this regard there is also a hadeeth which at-Tirmidhee narrates from Anas (radiyallaahu `anhu), who said that the Messenger of Allaah (salalllaahu `alayhi wa sallam) said,
"Each of you should ask for his needs from Allaah, even if the strap of your sandal breaks, because if Allaah does not facilitate it, it will never be possible."
Allaah the Most High says in His Book:
"...But ask Allaah for His bounty..." [4:32]
"And when the prayer is finished, then you may disperse through the land, and seek the Bounty of Allaah..." [62:10]
Although this aayah is in the context of the congreagational Friday prayer, its meaning applies to all the prayers. That is why- and Allaah knows best - the Prophet sallallaahu `alayhi wa sallam instructed the person entering the mosque to say,
"AllaahummaftaH lee abwaaba raHmatik" (O Allaah! open the doors of Your mercy for me)
and when leaving the mosque to say,
"Allaahumma innee as'aluka min faDlik" (O Allaah! I ask of You some of Your Bounty)
[Muslim, Aboo Daawood, an-Nasaa'ee, ad-Daarimee, ibn Maajah, Ahmad, Aboo 'Awaanah, Abdur-Razzaaq and al-Baihaqee]
Also the Friend of Allaah (i.e. Ibraaheem, `alayhis salaam) had said,
"...then seek sustenance from Allaah, serve Him, and be grateful to Him." [29:17]
This is a command, and a command signifies obligation. Therefore, to seek help from Allaah and to entreat to Him in the matter of livelihood and others is a fundamental principle. Furthermore, it is important in seeking a livelihood that one should acquire wealth with generosity of heart and not with greed so that he may be blessed in it. Neither should he make the wealth the primary aim; rather, he should regard wealth much as he regards the toilet, which he has need of but it has no place in his heart, and he only resorts to it when necessary.
A marfoo` (i.e. report consisting of a chain of narration that goes back to the Prophet, sallallaahu `alayhi wa sallam) hadeeth which is related by at-Tirmidhee and others states that, "He who begins the morning with this world as his greatest concern, Allaah disperses his collected gains and puts its loss in front of him, and only that of the world comes to him which is written for him. And he who begins the morning with the Hereafter as his greatest concern, Allaah gathers for him his works and creates richness in his heart due to them, and the world comes to him subserviently." [Related by at-Tirmidhee with a da`eef isnaad, but the hadeeth is saheeh due to the supporting narrations of ibn Maajah, Ibn Hibbaan and Ahmad]
One of the Salaf said, "Each of you is in need of the world, but you are in more need of your portion in the Hereafter. Therefore, if you are in search of your portion in the Hereafter first and foremost, then you will achieve your portion of the world in passing, such that it is taken care of as it comes."
Allaah the Exalted says:
"I have only created jinn and men that they may worship Me. No sustenance do I require of them, nor do I require that they should feed Me. For Allaah is He who gives (all) sustenance, Lord of Power, Steadfast (forever)." [51:56-58]

By Shaykh ul-Islaam ibn Taymiyyah rahimahullaah