From The Quran-
“When some trouble touches man, he cries to his Lord,
turning to Him in repentance: but when He bestows a favour
upon him as from Himself, (man) forgets what he cried and
prayed for before, and sets up partners to Allah, thus
misleading others from Allah’s Path. Say, ‘Enjoy your blasphemy
for a little while: verily you are (one) of the Companions of
the Fire!’ “. (Surah Az-Zumar 39:8)
Surat az Zumar.
[Lessons from this verse] We normally reserve turning in
repentance to when troubled times come upon us. No, we are
equally commanded to turn in repentance when the mercy of
Allah is showered upon us, because that is the time so many
people attribute that mercy to other then Allah.
