What is the ruling on a Muslim who abandons his son, denies his lineage, and leaves him to be raised in a Christian environment, and what is your guidance to him?

The child is attributed to his father, based on the Prophet's saying, "The child belongs to the bed, and for the fornicator is the stone." If the husband is certain or strongly suspects that the child is not his, he has the right to disown him through li'an (oath of condemnation). The child is not disowned merely by the husband's repudiation or the wife's confession of adultery, according to the majority of scholars.

The description of li'an is found in Surah An-Nur (24:6-9), where the husband testifies four times that he is truthful in accusing her of adultery, and the fifth time that the curse of Allah be upon him if he is a liar. The wife then testifies four times that he is a liar, and the fifth time that the wrath of Allah be upon her if he is truthful. The mula'anah (act of performing li'an) takes place in the mosque in the presence of a group of Muslims and the ruler.

The consequences of li'an are: averting the punishment for slander from the husband and the punishment for adultery from the wife, permanent separation between the spouses, and the disowning of the child from the husband, so that the child is attributed to his mother. Consequently, there is no inheritance or maintenance between them.

The husband should not resort to mula'anah and disown the child unless he is absolutely certain; otherwise, he would be sinful for wronging his child and exposing him to deviation.