The Mercy of Allah is Inclusive of the Believers and the Blasphemers in the Present Life and Specific to the Believers in the Afterlife

Allah the Exalted has Mercy on the believers and the blasphemers in the present life; His Mercy has encompassed all of them.  As for the afterlife, His Mercy will be specific to the believers.  Allah the Exalted Said:

﴿وَرَ‌حْمَتِي وَسِعَتْ كُلَّ شَيْءٍ فَسَأَكْتُبُهَا لِلَّذِينَ يَتَّقُونَ وَيُؤْتُونَ الزَّكَاةَ وَالَّذِينَ هُم بِآيَاتِنَا يُؤْمِنُونَ﴾

[which means] “My Mercy encompasses everything [in this life], and I will reserve it for those who have taqwa [in the next life],” meaning that in the present life His Mercy has encompassed every believer and blasphemer.  He Says, “I will reserve it for those who have taqwa,” meaning, “I will specify it for those who feared shirk and all the other types of blasphemy.”

Also, Allah the Exalted Said:

﴿وَنَادَىٰ أَصْحَابُ النَّارِ‌ أَصْحَابَ الْجَنَّةِ أَنْ أَفِيضُوا عَلَيْنَا مِنَ الْمَاءِ أَوْ مِمَّا رَ‌زَقَكُمُ اللَّـهُ قَالُوا إِنَّ اللَّـهَ حَرَّ‌مَهُمَا عَلَى الْكَافِرِ‌ينَ﴾

[which means] “The people of Hell will call out to the people of Paradise, “Pour some water on us, or something from what Allah has Provided you.” They will say, “Certainly Allah has Made both of them forbidden for the blasphemers,” meaning Allah Makes forbidden for the blasphemers that beneficial sustenance and the quenching water in the Afterlife.  That is because they neglected the greatest of the Rights of Allah, which has no replacement, and that is believing in Allah and His Messenger.

Furthermore, Allah Made entering Islam, which is the greatest endowment from Allah, easy; and this by uttering the two Shahadahs after knowing about Allah and His Messenger. He also made blasphemy easy; one word that is an indication of belittling Allah or His Religion would take the speaker out of belief and throw him into blasphemy, which is the worst situation. It is such a bad state that he would be to Allah more insignificant than the vermin and the beast.  It does not matter whether he spoke that word seriously, jokingly or angrily.  This has been explained in the books of fiqh and the reliable madhhabs, and they have judged that the one who utters such a word blasphemes.

Allah the Exalted Said:

﴿إِنَّ شَرَّ‌ الدَّوَابِّ عِندَ اللَّـهِ الَّذِينَ كَفَرُ‌وا فَهُمْ لَا يُؤْمِنُونَ﴾

[which means] “Certainly the worst of the beasts to Allah that walk the face of the earth are those who blaspheme; they are not believers.”