My husband insults Allaah the Almighty, is it obligatory for me to leave him?

All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.

Scholars unanimously agreed that a person who either jestingly, seriously or mockingly insults Allaah is considered a disbeliever. Allaah Says (what means): {And if you ask them, they will surely say, "We were only conversing and playing." Say, "Is it Allaah and His verses and His Messenger that you were mocking?" Make no excuse; you have disbelieved after your belief.}[Quran 9:65-66] 

However the majority of the scholars held the opinion that if a person repents to Allaah the Almighty, Allaah will accept his repentance. Some scholars lay a condition for this repentance to be accepted: that is, that the person does not commit this sin three times. If this sin is repeated three times the person’s repentance will not be accepted because it signifies the corruption of the person's beliefs and their indifference to Islam.

Even so, the soundest opinion is that the repentance of a person who insults Allaah will be accepted, despite any repetition of the act. That is because there are many Quranic verses and authentic Hadeeths that clearly support this opinion. Moreover, the repentance of an apostate is definitely accepted. Moreover, the Hanbali scholars hold the opinion that if an apostate performs the prayer, he will be judged to be a Muslim, unless his apostasy was due to the denial of an obligatory act of worship or a heavenly Book or the like.

Thus, if you know that this man has repented to Allaah the Almighty, or declared the Two Testimonies of Faith, or performed the prayers like all Muslims and became firm in them before your 'Iddah (post-marriage waiting period) expires, then you are still his wife. This is because the correct view of the scholars affirms that the separation of spouses, when one has apostated, depends on the expiry of the wife's post-marriage waiting period.

In conclusion, you should sit with your husband and explain to him the danger of this sin and inform him of the Fataawa on this matter. You may also explain to him that you are not ready to stay with him if he repeats this sin in the future.