Chapter on Apostasy
Man Lā Yaḥḍuruh al-Faqīh|Volume 3|Book 1|Chapter 54
وَ رَوَى فَضَالَةُ عَنْ أَبَانٍ أَنَّ أَبَا عَبْدِ اَللَّهِ عَلَيْهِ اَلسَّلاَمُ قَالَ: فِي اَلصَّبِيِّ إِذَا شَبَّ فَاخْتَارَ اَلنَّصْرَانِيَّةَ وَ أَحَدُ أَبَوَيْهِ نَصْرَانِيٌّ أَوْ جَمِيعاً مُسْلِمَيْنِ قَالَ "لاَ يُتْرَكُ وَ لَكِنْ يُضْرَبُ عَلَى اَلْإِسْلاَمِ ".
In a narration reported by Fadalah from Aban, Abu Abdullah عليه السلام said: "Regarding a child who grows up and chooses Christianity while one of his parents is a Christian or both of them are Muslims, he is not to be left (in that state), but rather he is compelled to follow Islam."
- Ṣaḥīḥ al-Faqīh