Insulting Allaah The Almighty
5-12-2007 | IslamWeb
Question:
What is the ruling on my neighbor who insults Allaah The Almighty?
Answer:
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.
There is a consensus of opinion among the Muslim scholars 
that if a Muslim insults Allaah The Almighty or Islam, he is outside the fold of Islam, even if he does the pillars of Islam such as praying. Consequently, the person concerned has become a non-Muslim. His marriage contract terminates as a result of his apostasy and his wife must be separated from him. It is impermissible to eat from any animal he slaughters. It is impermissible to pray the funeral prayer on him when he dies. He must not be buried in a Muslim graveyard. He must not inherit anyone and no Muslim is allowed to inherit him. Ibn Qudaamah 
from the Hambali school said that if a person insults Allaah The Almighty, he becomes a non-Muslim, whether or not he was joking. The same ruling applies to anyone deriding Allaah, His verses, His messengers or His books.
When Muhammad ‘Ulaysh Al-Maaliki was asked about a woman who insulted Islam, he said that she had become a non-Muslim.
Therefore, you should not treat this apostate kindly.