Assalam O Alaikum WaRahmatullahi WaBarakatuh,
Welcome to the forum!
Everything that happens to a believer is good or it has more good in it than bad. Alhamdulillah, it is always a win-win situation for the believer. How - Let's look at few hadith to understand this better:
Prophet (peace be upon him) said:
The affair of the believer is amazing! The whole of his life is beneficial, and that is only in the case of the believer. When good times come to him, he is thankful and it is good for him, and when bad times befall him, he is patient and it is also good for him. (narrated by Muslim).
Indeed, we all fall sick, get into accidents, or are saddened at times of despair. However, the believer easily overcomes such hardships. Prophet (peace be upon him) said:
When the believer is afflicted with pain, even that of a prick of a thorn or more, God forgives his sins. (narrated by Bukhari)
It is reported that Abu Hurayrah, the companion of the Prophet, had a favorite illness! He is reported to have said:
“There is no illness that afflicts me more beloved to me than fever; it enters every part of me and [because of it] Allah the Mighty and Sublime gives every part of me its share of reward. (narrated by Bukhari in Al-Adab Al-Mufrad).
Subhana’Allah, if only we could all celebrate when we got sick or something misfortunate happened to us!
In terms of hardship, we should look to the Quran for guidance as it states:
Those who patiently preserve will truly receive a reward without measure (Quran 39:10)
and
And bear in patience whatever maybe fall you: this, behold, is something to set one’s heart upon( Quran 31:17).
Understand these hadiths and verses of Quran and you will understand why everything what happens to a believer is always good. For disbelievers, it is a different story. They may have lot of wealth, power, beauty etc. in this life but these are means to cover their hearts from recognizing the obvious truth.
I hope you find this helpful.
Ma'aSalaam