Answer
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
Thanks for your interesting question. We implore Allah to forgive our sins and to reward and guide us to the best way through which we can attain Paradise in the Hereafter.
Not only the agonies of death reduce one’s sins, but even little afflictions are causes for sins being forgiven. Abu Sa`id Al-Khudri (may Allah be pleased with him) quoted the Prophet (peace and blessings be upon him) as saying, “Whenever a Muslim is afflicted by any hardship, be it chronic disease, grief, harm, a disaster, or even a thorn prick, Allah washes out some of his sins.” (Al-Bukhari and Muslim)
In another hadith, the Prophet (peace and blessings be upon him) is reported to have said, “Wondrous is the state of a believer; he is a winner at any rate. If he is given a blessing, he shows gratitude, which is good for him. If he is plagued with an affliction, he shows patience, which is good for him.” (Muslim)
Regarding your question, the late Saudi scholar Sheikh Muhammad Al-`Uthaymeen, states:
Yes, every sickness, difficulty, worry, or distress that befalls a Muslim person, even the prick of a thorn, is an expiation for his sins. Then, if he bears it patiently and seeks reward for that with Allah, in addition to the forgiveness of his sins, he will be rewarded for the patience with which he bears the calamity that has befallen him. It makes no difference whether that is at the time of death or before. Calamities are expiations of sins for the believers. Allah Almighty says, “And whatever of misfortune befalls you, it is because of what your hands have earned. And He pardons much.” (Ash-Shura 42:30)
“It is because of what your hands have earned” indicates that it is an expiation for the things we have done. The Prophet (peace and blessings be upon him) is reported to have said, “Whenever a Muslim is afflicted by any hardship, be it chronic disease, grief, harm, a disaster, or even a thorn prick, Allah washes out some of his sins.” (Al-Bukhari and Muslim).
Allah Almighty knows best.
Source: www.islamqa.info