There is a narration in Surah Kahaf that a person accompanying Prophet Musa killed a boy as per the
following Ayaat :--
Kahaf
فَانطَلَقَا حَتَّىٰ إِذَا لَقِيَا غُلَامًا فَقَتَلَهُ قَالَ أَقَتَلْتَ نَفْسًا زَكِيَّةً بِغَيْرِ نَفْسٍ لَّقَدْ جِئْتَ شَيْئًا نُّكْرًا
18:74
So they went on until, when they met a boy, he slew him. (Musa) said: Have you slain an innocent person otherwise than for manslaughter? Certainly you have done an evil thing.
وَأَمَّا الْغُلَامُ فَكَانَ أَبَوَاهُ مُؤْمِنَيْنِ فَخَشِينَا أَن يُرْهِقَهُمَا طُغْيَانًا وَكُفْرًا
18-80
And as for the boy, his parents were believers and we feared lest he should make disobedience and ingratitude to come upon them:
What kind of lesson we get from this incident?
Asalamu alykum brother Sardar Miyan
You may want to read this article called "Suffering"
And scroll down to the part that says " CAN WE EVEN BEGIN TO UNDERSTAND GOD'S WIDER SCHEME?"
"SUFFERING"
http://quransmessage.com/articles/suffering%20FM3.htm
Peace