Does the excuse of ignorance apply to those who insult Allaah, even though we live in an Islamic country?

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 is His slave and Messenger.

Insulting someone means saying something with the aim of ridiculing or belittlement.  All scholars agree that whoever insults Allaah the Almighty is considered a disbeliever, whether the person does so seriously, jokingly or sarcastically.  

Ibn Taymiyyah said that any Muslim who insults Allaah the Exalted must be executed, according to the opinion of all scholars. By doing so he becomes an apostate, which is even worse than a disbeliever, because the latter exalts Allaah and believes that his false religion is not an abuse or belittlement of Allaah the Exalted.  He concluded that all scholars agree that any Muslim who insults Allaah The Exalted must be killed. However, they disagree about whether repentance afterwards can be accepted:

Ibn Qudaamah mentioned that whoever insults Allaah the Almighty is considered a disbeliever, whether he does so seriously, jokingly or sarcastically. The same applies to those who mock Allaah the Exalted, His verses, His Books or His messengers. Allaah the Almighty Said (what means): {And if you ask them, they will surely say, "We were only conversing and playing." Say, "Is it Allah and His verses and His Messenger that you were mocking?" Make no excuse; you have disbelieved after your belief. If We pardon one faction of you - We will punish another faction because they were criminals.} [Quran 9:65, 66]

Imaam Maalik mentioned, on the authority of  Abu Al-Qaasim that any Muslim who insults Allaah the Almighty must be killed without being asked to repent, while the Shaafi‘i and Hanafi scholars are of the opinion that insulting  Allaah the Exalted is considered apostasy but if the person repents this will be accepted. 

None of the scholars, according to our knowledge, say that the excuse of ignorance applies to anyone insulting Allaah the Almighty. 

Ibn Taymiyyah mentioned that a disbeliever believes that his religion is the right one, so he calls others to it.  No disbeliever believes in what he considers insulting, disparagement or belittlement of Allaah The Exalted, even if the false religion is, in fact, insulting Allaah The Almighty. On the contrary, those who insult Allaah The Almighty intentionally show that they belittle and disparage Allaah the Exalted and violate His sanctity.  In addition, the person knows that they have committed an extremely atrocious sin, one that is about to rupture the heavens, split the earth and devastate the mountains.  This is the worst kind of disbelief. 

Ibn Taymiyyah also mentioned that even if the abuser believes that he does so while disbelieving in the existence of the Maker and His greatness but then repents, we should be certain that he is a liar because Allaah the Almighty made all His creation with a disposition to acknowledge His existence and to glorify Him. Therefore, there is no doubt or motivation that may encourage people to do this, instead  it is done for mockery, disparagement and rebellion against the Lord of the Worlds.  The origin of this behavior springs from a person with a devilish soul or a stupid person who does not glorify Allaah the Almighty. 

In conclusion, it is impossible for any person to be ignorant about the prohibition on insulting Allaah the Exalted.

However, a person might use a name and not know that it is a term of abuse, because this differs according to the customs and traditions of each country.  Therefore, if a person uses such terms concerning Allaah the Almighty and then apologizes the excuse is acceptable, but the person's intention and punishment (in the Hereafter) is known to Allaah the Almighty.

Allaah Knows best.