Why Drastic Decrease of Emaan after the Extreme Increase of Emaan

This Question has been running in my head these days a lot. Of course we are always tested but still I want to know what were some evil stuffs I did that led to my calamity. I surely am not innocent nor free of sins. When I think deeply, I find a few things that are common in some of us whose Emaan went down: 

1. Haughtiness
2. Pride
3. Arrogance
4. Claiming to have knowledge
5. Looking down on others
6. Thinking oneself perfect as being 100% Honest, Free of Shirk and Innovation for 100% surety.
7. Feeling too proud to accept advice or sound knowledge from someone else (whom he/she thinks to be not good enough)
8. Being Harsh
9. Making fun of those who are weak in Emaan and who sins openly (due to weakness of emaan)
10. Criticizing others who are lower in state of emaan and knowledge
11. Lack of humbleness and humility
12. Quickness to judge others to be sinners, misguided, astray, and other terms
13. (There are more, I am sure, but these are few all of us should look into inshaaAllah).

And you can see below the Description of the Slave of Ar-Rahman. Hence, when we know what caused our illness of weakness of Emaan, we can seek for cure to be sound in our Emaan. InshaaAllah.

Check Out this BOok:

15 Attributes Of Slaves Of The Most Beneficent by Sheikh Dr.Saalih Ibn Sa'd As-Suhaimi

63	وَعِبَادُ الرَّحْمَنِ الَّذِينَ يَمْشُونَ عَلَى الْأَرْضِ هَوْنًا وَإِذَا خَاطَبَهُمُ الْجَاهِلُونَ قَالُوا سَلَامًا And the slaves of the Most Beneficent (Allâh) are those who walk on the earth in humility and sedateness, and when the foolish address them (with bad words) they reply back with mild words of gentleness. (Al-Furqan 25:63) [Ibn Katheer | Tabari | Qurtubi]	Arabic
64	وَالَّذِينَ يَبِيتُونَ لِرَبِّهِمْ سُجَّدًا وَقِيَامًا And those who spend the night before their Lord, prostrate and standing. (Al-Furqan 25:64) [Ibn Katheer | Tabari | Qurtubi]	Arabic
65	وَالَّذِينَ يَقُولُونَ رَبَّنَا اصْرِفْ عَنَّا عَذَابَ جَهَنَّمَ إِنَّ عَذَابَهَا كَانَ غَرَامًا And those who say: "Our Lord! Avert from us the torment of Hell. Verily! Its torment is ever an inseparable, permanent punishment." (Al-Furqan 25:65) [Ibn Katheer | Tabari | Qurtubi]	Arabic
66	إِنَّهَا سَاءتْ مُسْتَقَرًّا وَمُقَامًا Evil indeed it (Hell) is as an abode and as a place to dwell. (Al-Furqan 25:66) [Ibn Katheer | Tabari | Qurtubi]	Arabic
67	وَالَّذِينَ إِذَا أَنفَقُوا لَمْ يُسْرِفُوا وَلَمْ يَقْتُرُوا وَكَانَ بَيْنَ ذَلِكَ قَوَامًا And those, who, when they spend, are neither extravagant nor niggardly, but hold a medium (way) between those (extremes). (Al-Furqan 25:67) [Ibn Katheer | Tabari | Qurtubi]	Arabic
68	وَالَّذِينَ لَا يَدْعُونَ مَعَ اللَّهِ إِلَهًا آخَرَ وَلَا يَقْتُلُونَ النَّفْسَ الَّتِي حَرَّمَ اللَّهُ إِلَّا بِالْحَقِّ وَلَا يَزْنُونَ وَمَن يَفْعَلْ ذَلِكَ يَلْقَ أَثَامًا And those who invoke not any other ilâh (god) along with Allâh, nor kill such life as Allâh has forbidden, except for just cause, nor commit illegal sexual intercourse and whoever does this shall receive the punishment. (Al-Furqan 25:68) [Ibn Katheer | Tabari | Qurtubi]	Arabic
69	يُضَاعَفْ لَهُ الْعَذَابُ يَوْمَ الْقِيَامَةِ وَيَخْلُدْ فِيهِ مُهَانًا The torment will be doubled to him on the Day of Resurrection, and he will abide therein in disgrace; (Al-Furqan 25:69) [Ibn Katheer | Tabari | Qurtubi]	Arabic
70	إِلَّا مَن تَابَ وَآمَنَ وَعَمِلَ عَمَلًا صَالِحًا فَأُوْلَئِكَ يُبَدِّلُ اللَّهُ سَيِّئَاتِهِمْ حَسَنَاتٍ وَكَانَ اللَّهُ غَفُورًا رَّحِيمًا Except those who repent and believe (in Islâmic Monotheism), and do righteous deeds, for those, Allâh will change their sins into good deeds, and Allâh is Oft-Forgiving, Most Merciful. (Al-Furqan 25:70) [Ibn Katheer | Tabari | Qurtubi]	Arabic
71	وَمَن تَابَ وَعَمِلَ صَالِحًا فَإِنَّهُ يَتُوبُ إِلَى اللَّهِ مَتَابًا And whosoever repents and does righteous good deeds, then verily, he repents towards Allâh with true repentance. (Al-Furqan 25:71) [Ibn Katheer | Tabari | Qurtubi]	Arabic
72	وَالَّذِينَ لَا يَشْهَدُونَ الزُّورَ وَإِذَا مَرُّوا بِاللَّغْوِ مَرُّوا كِرَامًا And those who do not witness falsehood, and if they pass by some evil play or evil talk, they pass by it with dignity. (Al-Furqan 25:72) [Ibn Katheer | Tabari | Qurtubi]	Arabic
73	وَالَّذِينَ إِذَا ذُكِّرُوا بِآيَاتِ رَبِّهِمْ لَمْ يَخِرُّوا عَلَيْهَا صُمًّا وَعُمْيَانًا And those who, when they are reminded of the Ayât (proofs, evidences, verses, lessons, signs, revelations, etc.) of their Lord, fall not deaf and blind thereat. (Al-Furqan 25:73) [Ibn Katheer | Tabari | Qurtubi]	Arabic
74	وَالَّذِينَ يَقُولُونَ رَبَّنَا هَبْ لَنَا مِنْ أَزْوَاجِنَا وَذُرِّيَّاتِنَا قُرَّةَ أَعْيُنٍ وَاجْعَلْنَا لِلْمُتَّقِينَ إِمَامًا And those who say: "Our Lord! Bestow on us from our wives and our offspring who will be the comfort of our eyes, and make us leaders for the Muttaqûn" (pious - see V.2:2 and the footnote of V.3:164)." (Al-Furqan 25:74) [Ibn Katheer | Tabari | Qurtubi]	Arabic
75	أُوْلَئِكَ يُجْزَوْنَ الْغُرْفَةَ بِمَا صَبَرُوا وَيُلَقَّوْنَ فِيهَا تَحِيَّةً وَسَلَامًا Those will be rewarded with the highest place (in Paradise) because of their patience. Therein they shall be met with greetings and the word of peace and respect. (Al-Furqan 25:75) [Ibn Katheer | Tabari | Qurtubi]	Arabic
76	خَالِدِينَ فِيهَا حَسُنَتْ مُسْتَقَرًّا وَمُقَامًا Abiding therein; excellent it is as an abode, and as a place to dwell. (Al-Furqan 25:76)