What is real definition of success in Islam?

Islam treats the term ‘success’ in a much deeper and vaster meaning of the term than simply attaining something as transient as wealth, or fame or position! Islam treats wealth, or fame, or position in the life of this world as a distribution of the bounty of the Merciful Lord to any amongst His slaves as He Pleases, and not a barometer of success!
Allah Says in the Holy Quran Chapter 17 Surah Israa verses 18-21:
18 If any do wish for the transitory things (of this life), We readily grant them--such things as We will, to such persons as We will: in the end have We provided Hell for them: they will burn therein disgraced and rejected.
19 Those who do wish for the (things of) the Hereafter, and strive therefore with all due striving, and have Faith; they are the ones whose striving is acceptable (to Allah).
20 Of the bounties of thy Lord, We bestow freely on all these, as well as those: the bounties of thy Lord are not closed (to anyone).
21 See how We have bestowed more on some than on others; but verily the Hereafter is more in rank and gradation, and more in excellence.
Not that Islam discourages its believers to demean or belittle these favors of fame and fortune from Allah Subhanah; but Islam definitely does not relate these to ‘success’!
Allah Says in the Holy Quran Chapter 28 Surah Qasas verse 77: "But seek with the (wealth) which Allah has bestowed on thee the Home of the Hereafter, nor forget thy portion in this world: but do thou good as Allah has been good to thee and seek not (occasions for) mischief in the land: for Allah loves not those who do mischief."
Islam treats the term ‘success’ in all its true manifestations; and guides to a path which will lead to ‘success’ or the accomplishment of one’s aim in this transient world, and in the eternal Hereafter; without separating the success of the world from the Hereafter! Islam guides to a Straight Path, which leads to success both in this world, and in the Hereafter. But without a doubt, Islam advocates and encourages its believers to strive and prefer the success of the Hereafter; for that is indeed what Allah Subhanah calls the Supreme Success!
Allah Says in the Holy Quran Chapter 3 Surah Ale-Imraan verse 185:Every soul shall have a taste of death! All of you shall get your full recompense only on the Day of Resurrection. Then only those will be Truly Successful, who escape the Fire of Hell and is admitted to the Gardens! As regards the life of this world, it is merely a thing that deceives!
Allah Says in the Holy Quran Chapter 61 Surah Saff verses 10-12:
10 O ye who believe! Shall I lead you to a bargain that will save you from a grievous Penalty?
11 That ye believe in Allah and His Messenger, and that ye strive (your utmost) in the Cause of Allah with your property and your persons: that will be best for you if ye but knew!
12 He will forgive you your sins and admit you to Gardens beneath which rivers flow, and to beautiful mansions in Gardens of Eternity: that is indeed the Supreme Achievement.
Allah Says in the Holy Quran Chapter 9 Surah Taubah verses 88-89:
88 But the Messenger and those who believe with him, strive with their wealth and their persons (in the Cause of Allah): for them are (all) good things: and it is they who will prosper.
89 Allah hath prepared for them Gardens, under which rivers flow, to dwell therein: that is the Supreme Felicity.
Allah Says in the Holy Quran Chapter 9 Surah Taubah verse 72: Allah hath promised to believers, men and women, Gardens under which rivers flow to dwell therein, and beautiful mansions in Gardens of everlasting bliss. But the Greatest Bliss is the Good Pleasure of Allah: that is the Supreme Felicity.

Thus, the elements of success as described by Allah Subhanah in the Glorious Quran relate to two basic and fundamental criterias:
Reprieve from fear, and Reprieve from grief.
And it is these two fundamental elements of success which are constantly promised to those who shall be fortunate enough to achieve the Supreme Felicity or Success in the life of the Hereafter: that they shall have no fear of anything to happen to them in the future, and nor shall they have grief for anything that happened to them in the past!
Allah Says in the Holy Quran Chapter 43 Surah Zukhruf verses 67-72:
67 Friends on that Day will be foes one to another, except the Righteous.
68 (Allah will Declare) “My devotees! no fear shall be on you that Day, nor shall ye grieve
69 (Being) those, who have believed in Our Signs, and bowed (their wills to Ours) in Islam.
70 Enter ye the Garden, ye and your wives, in (beauty and) rejoicing.”
71 To them will be passed round dishes and goblets of gold: there will be there all that the souls could desire, all that the eyes could delight in: and ye shall abide therein (for aye).
72 Such will be the Garden of which ye are made heirs, for your (good) deeds (in life).
Allah Says in the Holy Quran Chapter 35 Surah Fatir verses 33-35:
33 Gardens of Eternity will they enter: therein will they be adorned with bracelets of gold and pearls; and their garments there will be of silk.
34 And they will say: "Praise be to Allah, Who has removed from us (all) sorrow: for Our Lord is indeed Oft-Forgiving, Ready to appreciate (service):
35 "Who has out of His bounty settled us in a Home that will last: no toil, nor sense of weariness, shall touch us therein."
And these two all important elements of reprieve from fear and grief are such, that only, and I repeat, only, those who strive for success in the life of the Hereafter will taste these two elements of success even in the life of this world!
Allah Says in the Holy Quran Chapter 41 Surah Fusselat verses 30-32:
30 In the case of those who say "Our Lord is Allah", and further stand straight and steadfast, the Angels descend on them (from time to time): "Fear ye not!" (they suggest) "nor grieve! but receive the Glad Tidings of the Garden (of Bliss) the which ye were promised!
31 "We are your protectors in this life, and in the Hereafter: therein shall ye have all that your souls shall desire; therein shall ye have all that ye ask for!
32 "A hospitable gift from One: Oft-Forgiving, Most Merciful!"
Allah Says in the Holy Quran Chapter 46 Surah Ahqaaf verse 13:
13 Verily those who say "Our Lord is Allah", and remain firm (on that Path), on them shall be no fear, nor shall they grieve.
Thus, the one and only way to attain true success in the life of this world, is to aim and strive towards achieving success in the life of the Hereafter! Success in the life of this world, is nothing but a simple by-product of the success in the Hereafter.
And the simple formula of success, as stated by the Merciful Lord in His Glorious Quran, is that one sincerely believes in Allah Subhanah, follows and stands firm on the Path approved by Allah Subhanah; and he shall achieve that so elusive term and mirage which the world is engrossed in searching day in and day out: freedom from fear and reprieve from grief!
No amount of wealth in the world, and no amount of fame and accolades and status and positions can substitute the peace and tranquility one achieves when he stays firm and steadfast on the Straight Path of Allah Subhanah; where the All-Mighty Lord grants and bestows him the freedom of all fear except the fear of Allah Subhanah, and relieves his grief by His Solemn Promise to forgive all his sins of the past!
Allah Says in the Holy Quran Chapter 10 Surah Yunus verses 62-64:
62 Behold! Verily, on the friends of Allah there is no fear, nor shall they grieve;
63 Those who believe, and (constantly) guard against evil
64 For them are Glad Tidings in the life of the Present, and in the Hereafter: no change can there be in the Words of Allah. This is indeed the Supreme Felicity.
Such a person will be considered successful in this world, and in the Hereafter! Blessed and Fortunate indeed are those who have taken Allah Alone as their Lord, and stood firm on the Straight Path approved by Him.
Question 2C: who we consider as a successful person?
Allah Says in the Holy Quran Chapter 9 Surah Taubah verse 100:
100 The vanguard (of Islam), the first of those who forsook (their homes), and of those who gave them aid, and (also) those who follow them in (all) good deeds: well pleased is Allah with them ,as are they with Him: for them hath He prepared Gardens under which rivers flow to dwell therein for ever: that is the Supreme Felicity.
Allah Says in the Holy Quran Chapter 9 Surah Taubah verses 111-112:
111 Allah hath purchased of the believers their persons and their goods; for theirs (in return) is the Garden (of Paradise ): they fight in His cause and slay and are slain: a promise binding on Him in Truth through the Law, the Gospel, and the Qur`an: and who is more faithful to his covenant than Allah? Then rejoice in the bargain which ye have concluded: that is the Achievement Supreme.
112 Those that turn (to Allah) in repentance: that serve Him and praise Him; that wander in devotion to the Cause of Allah; that bow down and prostrate themselves in prayer; that enjoin good and forbid evil; and observe the limits set by Allah; (these do rejoice). So proclaim the glad tidings to the Believers.
Allah Says in the Holy Quran Chapter 4 Surah Nisaa verse 69:
69 All who obey Allah and the Messenger are in the company of those on whom is the Grace of Allah: of the Prophets, the sincere (lovers of truth), the witnesses (who testify), and the righteous (who do good): Ah! What a Beautiful Fellowship!
In the above beautiful Aayahs of the Glorious Quran, Allah Subhanah Himself States Who are the Truly Succesful in His Sight:
The Prophets are successful
The ‘Siddiqeen’ or the ‘sincere lovers of the Truth’ are successful
The ‘Shohadaa’ or the ‘martyrs’ and thus the ‘witnesses of Truth’ are successful
The ‘Saaleheen’ or the righteous doers of good are successful.
The True Believers are successful
May Allah Subhanah have mercy on you and us, guide you and us, make us firm on His Approved Path, and grant you and us the companionship of the Prophets, the Siddiqeen, the Shohadaa, the Saleheen and the True Believers in the Hereafter. Ameen.
Failure is the exact opposite of success! It is indeed amazing that the people who strive their utmost all their lives in the accumulation of wealth and fame of this world and give little or no importance to their everlasting life in the Hereafter, thinking they are following the pursuit of success; will reach their destination One Day only to realize that they followed nothing but a mirage and dreams of falsehood!
Allah Says in the Holy Quran Chapter 57 Surah Hadid verse 20:Know ye (all) that the life of this world is but play and amusement pomp and mutual boasting and multiplying (in rivalry) among yourselves of riches and children:
Allah Says in the Holy Quran Chapter 2 Surah Baqarah verse 200:There are men who say: "Our Lord! give us (thy bounties) in this world!", but they will have no portion in the hereafter.
Allah Says in the Holy Quran Chapter 42 Ash-Shura verse 20:Whoever seeks the harvest of the Hereafter, We do increase his harvest. And whoever seeks the harvest of this world, We do give him of it, but in the Hereafter he will have no share whatsoever.
Allah Says in the Holy Quran Chapter 9 Surah Taubah verse 63: Know they not that for those who oppose Allah and His Messenger is the fire of Hell, wherein they shall dwell? That is the Supreme Disgrace.
Allah Says in the Holy Quran Chapter 45 Surah Jathiyaa verses 7-11:
7 Woe to each sinful Dealer in Falsehoods:
8 He hears the Signs of Allah rehearsed to him, yet is obstinate and lofty as if he had not heard them: then announce to him a Penalty Grievous!
9 And when he learns something of Our Signs he takes them in jest: for such there will be a humiliating Penalty.
10 In front of them is Hell: and of no profit to them is anything they may have earned, nor any protectors they may have taken to themselves besides Allah: for them is a Tremendous Penalty.
11 This is (true) Guidance: and for those who reject the Signs of their Lord is a grievous Penalty of Abomination.
Allah Says in the Holy Quran Chapter 5 Surah Maidah verses 36-37:
36 As to those who reject faith if they had everything on earth, and twice repeated to give as ransom for the penalty of the Day of Judgement, it would never be accepted of them. Theirs would be a Grievous Penalty.
37 Their wish will be to get out of the fire, but never will they get out therefrom: their penalty will be one that endures.
Whatever written of Truth and benefit is only due to Allah’s Assistance and Guidance, and whatever of error is of me. Allah Alone Knows Best and He is the Only Source of Strength.