As for the fruits of putting one’s trust in Allaah (i.e. tawakkul), then they are many. The greatest of them is that Allaah will suffice him in whatever he seeks after. “And whoever puts his trust in Allaah, He will suffice him.” [Surah At-Talaaq: 3]
So whoever relegates his affairs to Allaah, relies on Him alone, and believes that no one can give him good or repel harm from him except Allaah, “He will suffice him.”
This means that Allaah will protect him from all harms since the recompense is based on the action a person does. So when someone puts his trust in Allaah in the correct manner, He rewards him by sufficing him and taking charge of his affairs. Allaah Himself takes charge of this individual’s affairs and does not relegate it to anyone else. This is the greatest fruit of tawakkul (reliance upon Allaah).
Allaah says: “O Prophet, Allaah is sufficient for you.” [Surah Al-Anfaal: 64]
And He says: “And if they intend to deceive you, then verily Allaah is sufficient for you. It is He who supported you with His help and with the believers.” [Surah Al-Anfaal: 62]
So in summary: The greatest fruit of putting one’s trust in Allaah is that Allaah will suffice and take care of whoever relies in Him. This is why Allaah informs us of His Prophet Nooh when he told his people: “If my staying with you and my reminding you of the verses of Allaah are hard on you, then I put my trust in Allaah. So devise your plot – you and your partners – and let not your plot be in doubt for you. Then pass your sentence on me and give me no respite.” [Surah Yoonus: 71]
Allaah informs us through the statement of these noble messenger that he challenged hispeople and their false deities to bring harm to him in some way. He did this because he had complete reliance on Allaah. And whoever puts his trust in Allaah, He will be sufficient for him.
Another fruit of relying upon Allaah is that it brings about loves from Allaah, as He says: “Verily, Allaah loves those who put their trust in Him.” [Surah Aali ‘Imraan: 159]
So if someone truthfully puts his trust in Allaah, Allaah will love him. And if Allaah loves this person, he will find success and happiness in this life and the next since he will be from among Allaah’s friends and allies.
Also from the fruits of putting one’s trust in Allaah is that a person will proceed in doing beneficial things and not fear or dread anyone except Allaah.
Another fruit of putting one’s trust in Allaah is that it encourages one to go out and seek sustenance or to acquire knowledge or to do any of the other beneficial things. The one who puts his trust in Allaah perseveres and puts his heart into seeking after the useful and necessary means of life because he knows that Allaah is with those who rely on Him and that He will aid them. So he perseveres in seeking after all of the beneficial things of this life and the Hereafter and he is not from those who are lazy and weak.
It is for this reason that the Companions were the bravest of people. They genuinely put their trust and reliance in Allaah to the point that they were able to conquer lands in the east and the west. They conquered lands through victory in battle and conquered hearts through calling them to Allaah. All of this was because they put their trust in Allaah and because they relied on Him. Allaah says: “O you who believe, whoever amongst you apostates from his religion, Allaah will bring a people whom He will love and they will love Him, humble towards the believers and stern towards the disbelievers, fighting in the Cause of Allaah and never fearing the blame of the blamers. That is the Grace of Allaah which He bestows upon whom He wills. And Allaah is All-Sufficient for His creatures’ needs, All-Knowing.” [Surah Al-Maa’idah: 54]
So they didn’t fear for the sake of Allaah the blame of the blamers since they relied on Him to the utmost degree and entrusted their affairs in Him absolutely. They did not turn to anyone else regardless if the people were content or discontent with it, so long as they continued to do what was pleasing to Allaah. It is stated in the hadeeth: “Whoever seeks to please Allaah by (doing something that is) displeasing (to) the people, Allaah becomes pleased with him and makes the people pleased with him. And whoever seeks to please the people by (doing something that is) displeasing (to) Allaah, Allaah becomes displeased with him and makes the people displeased with him.” 
So relying upon Allaah, putting one’s trust in Him, and entrusting one’s affairs to Him is the foundation of Tawheed. It is the foundation of actions. And it is the foundation of goodness. This is why Allaah made it a condition of Faith, where He says: “So in Allaah put your trust if you are truly believers.” [Surah Al-Maa’idah: 23]
 Reported by Ibn Hibbaan in his Saheeh (1/435) and At-Tirmidhee in his Sunan (7/133) in a similar narration, both on the authority of ‘Aa’ishah; Others reported it as well.
Shaykh Saalih bin Fawzaan Al-Fawzaan, may Allah preserve him
Source: Haqeeqat-ut-Tawakkul, pg. 35-42. Translation taken from www.al-ibaanah.com (offline)