Whoever does not believe that the kaafirs are kaafirs is himself a kaafir

Praise be to Allah.

Yes, this is correct. Whoever is not convinced that the person who disbelieves in the religion of Allah is a kaafir, does not believe what Allah has told us about their being kaafirs, and he does not believe that the religion of Islam abrogates all previous religions and that all people must follow this religion no matter what their religion was before.

Allah says:

{وَمَن يَبْتَغِ غَيْرَ ٱلْإِسْلَـٰمِ دِينًۭا فَلَن يُقْبَلَ مِنْهُ وَهُوَ فِى ٱلْأَخِرَةِ مِنَ ٱلْخَـٰسِرِينَ}

'Translation' {And whoever seeks a religion other than Islam, it will never be accepted of him, and in the Hereafter he will be one of the losers} [Aal ‘Imraan:85].

{قُلْ يَـٰٓأَيُّهَا ٱلنَّاسُ إِنِّى رَسُولُ ٱللَّهِ إِلَيْكُمْ جَمِيعًا}  

'Translation' {Say (O Muhammad): “O mankind! Verily, I am sent to you all as the Messenger of Allah} [al-A'raaf  from the verse:158].

Al-Qaadi ‘Ayyaad said: "hence we regard as a kaafir everyone who follows a religion other than the religion of the Muslims, or who agrees with them, or who has doubts, or who says that their way is correct, even if he appears to be a Muslim and believes in Islam and that every other way is false, he is a kaafir" (Al-Shifaa' bi Ta'reef Huqooq al-Mustafaa [2/1071]).

Shaykh Muhammad ibn 'Abd al-Wahhaab (may Allah have mercy on him) said: "Know that among the greatest things that can nullify Islam are ten things:

Associating othes in worship of Allah alone, Who has no partner or associate. The evidence ofr that is the aayah:

{إِنَّ ٱللَّهَ لَا يَغْفِرُ أَن يُشْرَكَ بِهِۦ وَيَغْفِرُ مَا دُونَ ذَ‌ ٰلِكَ لِمَن يَشَآءُ}

'Translation' {Verily, Allah forgives not (the sin of) setting up partners (in worship) with Him, but He forgives whom He wills, sins other than that} [al-Nisaa':116].

This also includes offering scarifices to other than Allah, such as to the jinn or at graves.

Whoever regards others as intermediaries between him and Allah and calls upon them to ask them to intercede for him, is a kaafir according to scholarly consensus.

Whoever does not regard the Mushrikeen as kaafirs or doubts that they are kaafirs or regard their way as correct, is a kaafir according to scholarly consensus".

After enumerating them, he said (may Allah have mercy on him): "In the case of all these things that nullify Islam, there is no difference whether a person is joking or is serious or is afraid, except in cases where he is forced to do something. All of them are among the things that are very dangerous and which happen very often. The Muslim has to beware of them and fear them happening to him. We seek refuge with Allah from the things that earn His wrath and His painful prunishment, May Allah bless Muhammad" (Mu'allafaat al-Shaykh Muhammad ibn 'Abd al-Wahhaab [212, 213]).

Shirk and kufr are the same when it comes to the ruling (hukm)

Ibn Hazm said: "Kufra and shirk are the same; every kaafir is a mushrik and every mushrik is a kaafir. This is the view of al-Shaafa’ and others" (al-Fisl [3/124]).

The Jews and Christians are kuffaar and mushrikeen. Allah says:

{وَقَالَتِ ٱلْيَهُودُ عُزَيْرٌ ٱبْنُ ٱللَّهِ وَقَالَتِ ٱلنَّصَـٰرَى ٱلْمَسِيحُ ٱبْنُ ٱللَّهِ ۖ ذَ‌ ٰلِكَ قَوْلُهُم بِأَفْوَ‌ ٰهِهِمْ ۖ يُضَـٰهِـُٔونَ قَوْلَ ٱلَّذِينَ كَفَرُوا۟ مِن قَبْلُ ۚ قَـٰتَلَهُمُ ٱللَّهُ ۚ أَنَّىٰ يُؤْفَكُونَ . ٱتَّخَذُوٓا۟ أَحْبَارَهُمْ وَرُهْبَـٰنَهُمْ أَرْبَابًۭا مِّن دُونِ ٱللَّهِ وَٱلْمَسِيحَ ٱبْنَ مَرْيَمَ وَمَآ أُمِرُوٓا۟ إِلَّا لِيَعْبُدُوٓا۟ إِلَـٰهًۭا وَ‌ ٰحِدًۭا ۖ لَّآ إِلَـٰهَ إِلَّا هُوَ ۚ سُبْحَـٰنَهُۥ عَمَّا يُشْرِكُونَ}

'Translation' {And the Jews say: ‘Uzair (Ezra) is the son of Allah, and the Christians say: Messiah is the son of Allah. That is their saying with their mouths, resembling the saying of those who disbelieved aforetime. Allah's Curse be on them, how they are deluded away from the truth! They (Jews and Christians) took their rabbis and their monks to be their lords besides Allah (by obeying them in things which they made lawful or unlawful according to their own desires without being ordered by Allah), and (they also took as their Lord) Messiah, son of Maryam (Mary), while they (Jews and Christians) were commanded [in the Tauraat (Torah) and the Injeel (Gospel)] to worship none but One Ilaah (God- Allah) Laa ilaaha illa Huwa (none has the right to be worshipped but He). Praise and glory be to Him (far above is He) from having the partners they associate (with Him)} [al-Tawbah:30-31].

It was reported from Abu Hurayrag that the Messenger of Allah (peace and blessings of Allah be upon him) said: «By the One is Whose hand is the soul of Muhammad, not one of this nation, Jew or Christian, will hear of me and will die without having believed in that with which I have been sent, but he will be one of the dwellers of Hell fire» (Narrated by Muslim, [153]).

Whoever says that the Jews are not kaafirs is disbelieving in the words of Allah:

{وَأُشْرِبُوا۟ فِى قُلُوبِهِمُ ٱلْعِجْلَ بِكُفْرِهِمْ}

'Translation' {And their hearts absorbed (the worship of) the calf because of their disbelief} [al-Baqarah:93].

{مِّنَ ٱلَّذِينَ هَادُوا۟ يُحَرِّفُونَ ٱلْكَلِمَ عَن مَّوَاضِعِهِۦ وَيَقُولُونَ سَمِعْنَا وَعَصَيْنَا وَٱسْمَعْ غَيْرَ مُسْمَعٍۢ وَرَ‌ ٰعِنَا لَيًّۢا بِأَلْسِنَتِهِمْ وَطَعْنًۭا فِى ٱلدِّينِ ۚ وَلَوْ أَنَّهُمْ قَالُوا۟ سَمِعْنَا وَأَطَعْنَا وَٱسْمَعْ وَٱنظُرْنَا لَكَانَ خَيْرًۭا لَّهُمْ وَأَقْوَمَ وَلَـٰكِن لَّعَنَهُمُ ٱللَّهُ بِكُفْرِهِمْ}

'Translation' {Among those who are Jews, there are some who displace words from (their) right places and say: "We hear your word (O Muhammad) and disobey", and "Hear and let you (O Muhammad) hear nothing". And Raa'ina [in Arabic it means "Be careful, listen to us, and we listen to you", whereas in Hebrew, it means "an insult"] with a twist of their tongues and as a mockery of the religion (Islam). And if only they had said: "We hear and obey", and "Do make us understand", it would have been better for them, and more proper; but Allah has cursed them for their disbelie} [al-Nisa' from the verse:46].

{فَبِمَا نَقْضِهِم مِّيثَـٰقَهُمْ وَكُفْرِهِم بِـَٔايَـٰتِ ٱللَّهِ وَقَتْلِهِمُ ٱلْأَنۢبِيَآءَ بِغَيْرِ حَقٍّۢ وَقَوْلِهِمْ قُلُوبُنَا غُلْفٌۢ ۚ بَلْ طَبَعَ ٱللَّهُ عَلَيْهَا بِكُفْرِهِمْ فَلَا يُؤْمِنُونَ إِلَّا قَلِيلًۭا . وَبِكُفْرِهِمْ وَقَوْلِهِمْ عَلَىٰ مَرْيَمَ بُهْتَـٰنًا عَظِيمًۭا . وَقَوْلِهِمْ إِنَّا قَتَلْنَا ٱلْمَسِيحَ عِيسَى ٱبْنَ مَرْيَمَ رَسُولَ ٱللَّهِ وَمَا قَتَلُوهُ وَمَا صَلَبُوهُ وَلَـٰكِن شُبِّهَ لَهُمْ ۚ وَإِنَّ ٱلَّذِينَ ٱخْتَلَفُوا۟ فِيهِ لَفِى شَكٍّۢ مِّنْهُ ۚ مَا لَهُم بِهِۦ مِنْ عِلْمٍ إِلَّا ٱتِّبَاعَ ٱلظَّنِّ ۚ وَمَا قَتَلُوهُ يَقِينًۢا}

'Translation' {Because of their breaking the covenant, and of their rejecting the Ayaat (proofs, evidences, verses, lessons, signs, revelations, etc.) of Allah, and of their killing the Prophets unjustly, and of their saying: "Our hearts are wrapped (with coverings, i.e. we do not understand what the Messengers say)"- nay, Allah has set a seal upon their hearts because of their disbelief, so they believe not but a little. And because of their (Jews) disbelief and uttering against Maryam (Mary) a grave false charge (that she has committed illegal sexual intercourse);  And because of their saying (in boast), "We killed Messiah 'Eesaa (Jesus), son of Maryam (Mary), the Messenger of Allah",- but they killed him not, nor crucified him, but it appeared so to them the resemblance of 'Eesaa (Jesus) was put over another man (and they killed that man)]} [al-Nisa':155-157].

{إِنَّ ٱلَّذِينَ يَكْفُرُونَ بِٱللَّهِ وَرُسُلِهِۦ وَيُرِيدُونَ أَن يُفَرِّقُوا۟ بَيْنَ ٱللَّهِ وَرُسُلِهِۦ وَيَقُولُونَ نُؤْمِنُ بِبَعْضٍۢ وَنَكْفُرُ بِبَعْضٍۢ وَيُرِيدُونَ أَن يَتَّخِذُوا۟ بَيْنَ ذَ‌ ٰلِكَ سَبِيلًا. أُو۟لَـٰٓئِكَ هُمُ ٱلْكَـٰفِرُونَ حَقًّۭا ۚ وَأَعْتَدْنَا لِلْكَـٰفِرِينَ عَذَابًۭا مُّهِينًۭا}

'Translation' {Verily, those who disbelieve in Allah and His Messengers and wish to make distinction between Allah and His Messengers (by believing in Allah and disbelieving in His Messengers) saying, "We believe in some but reject others", and wish to adopt a way in between. They are in truth disbelievers. And We have prepared for the disbelievers a humiliating torment” [al-Nisa':150-151]

Whoever says that the Christians are not kuffaar is disbelieving in the words of Allah:

{لَّقَدْ كَفَرَ ٱلَّذِينَ قَالُوٓا۟ إِنَّ ٱللَّهَ هُوَ ٱلْمَسِيحُ ٱبْنُ مَرْيَمَ}

'Translation' {Surely, in disbelief are they who say that Allah is the Messiah, son of Maryam (Mary)} [al-Maa'idah from the verse:17].

{لَّقَدْ كَفَرَ ٱلَّذِينَ قَالُوٓا۟ إِنَّ ٱللَّهَ ثَالِثُ ثَلَـٰثَةٍۢ ۘ وَمَا مِنْ إِلَـٰهٍ إِلَّآ إِلَـٰهٌۭ وَ‌ ٰحِدٌۭ ۚ وَإِن لَّمْ يَنتَهُوا۟ عَمَّا يَقُولُونَ لَيَمَسَّنَّ ٱلَّذِينَ كَفَرُوا۟ مِنْهُمْ عَذَابٌ أَلِيمٌ}

'Translation' {Surely, disbelievers are those who said: "Allah is the third of the three (in a Trinity)". But there is no Ilaah (god) (none who has the right to be worshipped) but One Ilaah (God- Allah). And if they cease not from what they say, verily, a painful torment will befall on the disbelievers among them} [al-Maa'idah:73].

And he is disbelieving in the words of Allah concerning the Jews and Christians who do not believe in our Prophet or follow him:

{إِنَّ ٱلَّذِينَ يَكْفُرُونَ بِٱللَّهِ وَرُسُلِهِۦ وَيُرِيدُونَ أَن يُفَرِّقُوا۟ بَيْنَ ٱللَّهِ وَرُسُلِهِۦ وَيَقُولُونَ نُؤْمِنُ بِبَعْضٍۢ وَنَكْفُرُ بِبَعْضٍۢ وَيُرِيدُونَ أَن يَتَّخِذُوا۟ بَيْنَ ذَ‌ ٰلِكَ سَبِيلًا. أُو۟لَـٰٓئِكَ هُمُ ٱلْكَـٰفِرُونَ حَقًّۭا ۚ وَأَعْتَدْنَا لِلْكَـٰفِرِينَ عَذَابًۭا مُّهِينًۭا} 

'Translation' {Verily, those who disbelieve in Allah and His Messengers and wish to make distinction between Allah and His Messengers (by believing in Allah and disbelieving in His Messengers) saying, "We believe in some but reject others", and wish to adopt a way in between.  They are in truth disbelievers. And We have prepared for the disbelievers a humiliating torment” [al-Nisa':150-151]

What is there left to say after these clear statements from Allah, may He be exalted? We ask Allah to guide us. May Allah bless our Prophet Muhammad.

Sheikh Muhammed Salih Al-Munajjid.