Does repentance bring back the reward for what was lost because of showing off?

There is evidence in the Sunnah to indicate that if a person
did a righteous deed whilst he was a kaafir, then he repented and became
Muslim, there will be recorded for him after his repentance the reward of
the righteous deeds that he did before, as if he did them in Islam. This is
the great generosity of Allaah and His immense bounty and kindness. Although
some scholars disagreed with that, this is the correct view and it is the
apparent meaning of the saheeh Sunnah. 

It was narrated from Hakeem ibn Hizaam (may Allaah be pleased
with him) that he said: I said: O Messenger of Allaah, what do you think of
things that I did as acts of worship during the Jaahiliyyah such as giving
charity, freeing slaves and upholding the ties of kinship – is there any
reward for them? The Messenger of Allaah (blessings and peace of Allaah be
upon him) said: “You have become Muslim with all your previous virtues.” 

Narrated by al-Bukhaari (1436) and Muslim (123). 

Al-Haafiz ibn Rajab al-Hanbali (may Allaah have mercy on him)
said, commenting on this hadeeth: 

If a person did a righteous deed, then he did a bad deed
which cancelled it out, then he repented, then the reward that was lost
because of his bad deed will be restored to him. End quote. 

Fath al-Baari by Ibn Rajab
(1/146) 

Shaykh al-Islam Ibn Taymiyah (may Allaah be pleased with him)
said: 

If the hypocrite or show-off repents, does he have to repeat
(prayers etc), or will his repentance have the effect of reversal on the
deeds he did before that, so that he will be rewarded for them, or is it
that he does not have to repeat anything and will not be rewarded? 

As for repeating, the hypocrite does not have to do it at
all, because a group of hypocrites repented from hypocrisy at the time of
the Messenger of Allaah and he did not order any of them to repeat. And
Allaah says (interpretation of the meaning):

“and they could not find any cause to do so except that
Allaah and His Messenger had enriched them of His Bounty. If then they
repent, it will be better for them, but if they turn away; Allaah will
punish them with a painful torment in this worldly life and in the
Hereafter”

[al-Tawbah 9:74]

Moreover, the hypocrite is inwardly a kaafir, so when he
believes he is forgiven what he did before, so he does not have to make
anything up, just as that is not required of the one who was outwardly a
kaafir when he becomes Muslim. 

With regard to his reward for what he did before, when he
repents he is like the kaafir if he did righteous deeds when he was a kaafir
then became Muslim — will he be rewarded for it? In al-Saheehayn it
is narrated that the Prophet (blessings and peace of Allaah be upon him)
said to Hakeem ibn Hizaam: “You have become Muslim with all your previous
virtues.” 

With regard to the show-off, if he repents from showing off,
even though he believed it was obligatory, then it is similar to the issue
of what we are speaking of here, which is the issue of one who did not carry
out an obligatory duty, even if he was not inwardly a kaafir; obliging him
to make ups or repeat things is a major deterrent to repentance. End quote. 

Majmoo’ al-Fataawa (22/20-21) 

He also said (may Allaah have mercy on him): 

The one who repents from sin is like the one who did not sin,
and if the sin is erased then the punishment and consequences are also
erased. Negation of good deeds is one of the consequences of sin. End
quote. 

Sharh al-‘Umdah (1/39). 

Ibn Qayyim al-Jawziyyah (may Allaah have mercy on him) said: 

Chapter: if his recent bad deeds supersede his past good
deeds and cancel them out, then he repents sincerely from them, his good
deeds are restored to him and he does not come under the same ruling as one
who starts all over again, rather it is said to him: You have repented on
the basis that what you did previously of good deeds (will be kept for you).
The good deeds that he did in Islam are greater than the good deeds that the
kaafir did when he was a kaafir, such as freeing slaves, giving charity and
upholding the ties of kinship. Hakeem ibn Hizaam said: O Messenger of
Allaah, what do you think of things that I did as acts of worship during the
Jaahiliyyah such as giving charity, freeing slaves and upholding the ties of
kinship – is there any reward for them? The Messenger of Allaah (blessings
and peace of Allaah be upon him) said: “You have become Muslim with all your
previous virtues.” 

That is because sins that come between two acts of obedience
are erased by means of repentance, so it becomes as if they never happened,
and the two acts of obedience come together and will be counted together.
And Allaah knows best. End quote. 

Madaarij al-Saalikeen (1/282) 

And Allaah knows best.