What is the ruling on cursing the religion of Jews and Christians?

It is forbidden to curse the deities of the disbelievers and their beliefs, due to Allah Almighty's prohibition of that in His statement: "And do not insult those they invoke other than Allah, lest they insult Allah in enmity without knowledge." (Quran 6:108) Al-Qurtubi clarified that this ruling remains in effect. Thus, if a disbeliever is in a position of strength, and there is a fear that cursing them might lead to their cursing Islam, the Prophet, or Allah, then it is not permissible for a Muslim to curse their crosses, their religion, or their churches, nor to engage in anything that might lead to that; because it is tantamount to inciting disobedience.

However, there is no impediment for specialists to explain the errors in their books and beliefs to dispel misconceptions, and this act may be a collective obligation (fard kifa'i).