Abu Hurairah reported the Messenger of Allah ﷺ as saying:

Every child is born on Islam, but his parents make him a Jew and a Christian, just as a beast is born whole. Do you find some among them (born) maimed? The people asked : Messenger of Allah! What do you think about the one who died while he was young? He replied : Allah knows best what he was going to do.

حَدَّثَنَا الْقَعْنَبِيُّ، عَنْ مَالِكٍ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ ﷺ " كُلُّ مَوْلُودٍ يُولَدُ عَلَى الْفِطْرَةِ فَأَبَوَاهُ يُهَوِّدَانِهِ وَيُنَصِّرَانِهِ كَمَا تَنَاتَجُ الإِبِلُ مِنْ بَهِيمَةٍ جَمْعَاءَ هَلْ تُحِسُّ مِنْ جَدْعَاءَ " . قَالُوا يَا رَسُولَ اللَّهِ أَفَرَأَيْتَ مَنْ يَمُوتُ وَهُوَ صَغِيرٌ قَالَ " اللَّهُ أَعْلَمُ بِمَا كَانُوا عَامِلِينَ " .