Allah ta^ala said in Surat Al-Fath, Ayah 13:
ومن لم يؤمن بالله ورسوله فإنا أعتدنا للكافرين سعيراً
This Ayah means: The one who does not join the belief in Allah with the belief in the Messenger of Allah, is a blasphemer deserving the torture of Hellfire.
This verse contains explicit proof that the one who does not believe in Muhammad is a blasphemer. So, whoever disputes this matter is opposing the Qur’an, and whoever opposes the Qur’an is a blasphemer.
The general meaning of the First Testification, ‘No one is God except Allah’, is that, I admit by my tongue and believe in my heart that the One Who deserves to be worshipped is Allah alone.
The general meaning of the Second Testification, ‘Muhammad is the Messenger of Allah’, is that, I admit by my tongue and believe in my heart that Muhammad, sallallahu ^alayhi wa sallam, is sent by Allah as a messenger to the entire world i.e., both to the humans and jinn.
Therefore, what is meant by the two testifications is the denial of the status of godhood to other than Allah and to affirm the status of godhood to Allah. That is, to affirm that no one deserves to be worshipped except Allah along with admitting and believing in the prophethood of Muhammad, because the one who does not believe in the prophethood of Muhammad is a not a believer.
One has to believe that Allah sent Prophet Muhammad as a messenger to all the humans and the jinn,to the Arabs and the non-Arabs.
Moreover, one has to believe that the Prophet is truthful in all that which he conveyed from Allah ta^ala so that the people would believe in the shari^ah he brought to them, and follow him.
It is obligatory to join the belief in the Prophethood of Muhammad with the testification that no one is God except Allah. And this is the least that is needed for one to escape the everlasting life in Hellfire.
Falsely, some non-believers say that they will be given a reward in the Hereafter better than the reward which the believers will receive. This is not case. Allah belied them in the Holy Qur’an in Ayah 35 of Suratul-Qalam. The Ayah means: Shall We then make the Muslims like the disbelievers. That is, they will never be equal.
Some blasphemers among the people of Makkah asked the Prophet to worship their idols for one year and then they would worship Allah for one year. Allah revealed suratul-Kafirun, affirming that this shall not happen.
shows the proof that he was ordered by Allah to say to them:
(يا أيُّها الكافرون)
(لا أَعْبُدُ مَا تَعْبُدُونَ)
Now and for the rest of my life, I will never fulfil your request that I worship the idols that you worship.
(ولا أَنْتُمْ عَابِدُونَ مَا أَعْبُدُ)
Also, you will never worship Allah now or in the future. For, Allah knew eternally that they shall not believe.
(ولا أَنَا عَابِدٌ مَا عَبَدْتُمْ)
This is a repetition of the meaning contained in the previous Ayah. This Ayah verifies that the blasphemers will not achieve their greedy ambitions to turn Prophet Muhammad away from Islam. Also, that they will never embrace Islam, will never believe, and will die as blasphemers.
(ولا أَنْتُمْ عَابِدُونَ مَا أَعْبُدُ)
This is a repetition of the meaning contained in the third Ayah and it affirms the meaning in Ayah 3 and 4.
(لَكُمْ دِينُكُمْ وَلِيَ دِينِ)
This Ayah contains a threat. (لَكُمْ دِينُكُمْ) means: You have your untrue religion of associating partners with Allah, which you follow and implement. (وَلِيَ دِينِ) means: I have the True Religion of Islam. That is, you have your blasphemy of shirk (associating partners with Allah)and I have my belief of clearing Allah of having a partner. This demonstrates Prophet Muhammad’s ultimate denial of their false belief. This threat is similar to the threat mentioned in Ayah 29 of Suratul-Kahf:
(فَمَنْ شَاءَ فَلْيُؤْمِنْ وَمَنْ شَاءَ فَلْيَكْفُرْ)
This Ayah does not mean that the one who chooses to be a believer is the same as the one who chooses blasphemy. Rather, the meaning entails that the believer is rewarded and the blasphemer will be tortured. The continuation of the Ayah is:
(إِنَّا أَعْتَدْنَا لِلظَّالِمِينَ نَارًا أَحَاطَ بِهِمْ سُرَادِقُهَا)
This means:We have prepared for the blasphemers a fire that surrounds them.
We ask Allah to keep us steadfast on the Religion of Islam and end our life on piety and righteousness, Ameen.