Increasing and decreasing faith

إِنَّمَا ٱلْمُؤْمِنُونَ ٱلَّذِينَ إِذَا ذُكِرَ ٱللَّهُ وَجِلَتْ قُلُوبُهُمْ وَإِذَا تُلِيَتْ عَلَيْهِمْ ءَايَٰتُهُۥ زَادَتْهُمْ إِيمَٰنًۭا وَعَلَىٰ رَبِّهِمْ يَتَوَكَّلُونَ

For, Believers are those who, when Allah is mentioned, feel a tremor in their hearts, and when they hear His signs rehearsed, find their faith strengthened, and put (all) their trust in their Lord;

وَإِذَا مَآ أُنزِلَتْ سُورَةٌۭ فَمِنْهُم مَّن يَقُولُ أَيُّكُمْ زَادَتْهُ هَٰذِهِۦٓ إِيمَٰنًۭا ۚ فَأَمَّا ٱلَّذِينَ ءَامَنُوا۟ فَزَادَتْهُمْ إِيمَٰنًۭا وَهُمْ يَسْتَبْشِرُونَ

Whenever there cometh down a sura, some of them say: "Which of you has had His faith increased by it?" Yea, those who believe,- their faith is increased and they do rejoice.

نَّحْنُ نَقُصُّ عَلَيْكَ نَبَأَهُم بِٱلْحَقِّ ۚ إِنَّهُمْ فِتْيَةٌ ءَامَنُوا۟ بِرَبِّهِمْ وَزِدْنَٰهُمْ هُدًۭى

We relate to thee their story in truth: they were youths who believed in their Lord, and We advanced them in guidance:

وَيَزِيدُ ٱللَّهُ ٱلَّذِينَ ٱهْتَدَوْا۟ هُدًۭى ۗ وَٱلْبَٰقِيَٰتُ ٱلصَّٰلِحَٰتُ خَيْرٌ عِندَ رَبِّكَ ثَوَابًۭا وَخَيْرٌۭ مَّرَدًّا

"And Allah doth advance in guidance those who seek guidance: and the things that endure, Good Deeds, are best in the sight of thy Lord, as rewards, and best in respect of (their) eventual return."

وَٱلَّذِينَ ٱهْتَدَوْا۟ زَادَهُمْ هُدًۭى وَءَاتَىٰهُمْ تَقْوَىٰهُمْ

But to those who receive Guidance, He increases the (light of) Guidance, and bestows on them their Piety and Restraint (from evil).

هُوَ ٱلَّذِىٓ أَنزَلَ ٱلسَّكِينَةَ فِى قُلُوبِ ٱلْمُؤْمِنِينَ لِيَزْدَادُوٓا۟ إِيمَٰنًۭا مَّعَ إِيمَٰنِهِمْ ۗ وَلِلَّهِ جُنُودُ ٱلسَّمَٰوَٰتِ وَٱلْأَرْضِ ۚ وَكَانَ ٱللَّهُ عَلِيمًا حَكِيمًۭا

It is He Who sent down tranquillity into the hearts of the Believers, that they may add faith to their faith;- for to Allah belong the Forces of the heavens and the earth; and Allah is Full of Knowledge and Wisdom;-