What is the meaning of the word Kafir in Quran?

Answer 1

Kafir is an Arabic word that means unbeliever of some fact or truth. The root of the Kafir word is the verb 'kafar' that means to cover on some truth to hide it or it means simply to disbelieve.

Also, it means to deny a truth. A person who denies the favors of Allah is said to be "kafir". So, Kafir is also the opposite of the grateful thankful person.

In this sense Quran mentions kafir on those who hide the truth, although they know it, and insist on disbelieving and on denying submitting to God (Allah in Arabic) as the one and only one God, with no partner, no son, no companion, no associate, and no resemblance.

Christians and Jews, in principal, are neither called in Quran as kafir nor as unbelievers. They are generally called 'people of the Scripture' as they are the holders of the holy books: The Bible and the Torah respectively. Quran says on people of the book (Christians and Jews):

وَإِنَّ مِنْ أَهْلِ الْكِتَابِ لَمَن يُؤْمِنُ بِاللَّـهِ وَمَا أُنزِلَ إِلَيْكُمْ وَمَا أُنزِلَ إِلَيْهِمْ خَاشِعِينَ لِلَّـهِ لَا يَشْتَرُونَ بِآيَاتِ اللَّـهِ ثَمَنًا قَلِيلًا ۗ أُولَـٰئِكَ لَهُمْ أَجْرُهُمْ عِندَ رَبِّهِمْ ۗ إِنَّ اللَّـهَ سَرِيعُ الْحِسَابِ ﴿١٩٩﴾

Meaning English translation:

{And indeed, among the People of the Scripture are those who believe in Allah (God) and what was revealed to you and what was revealed to them, [being] humbly submissive to Allah. They do not exchange the verses of Allah for a small price. Those will have their reward with their Lord. Indeed, Allah is swift in account. (199)}

[Quran, chapter 3, verse 199]

Quran says that who claims that Jesus is God or son of God or who believes in the Trinity has disbelieved:

لَقَدْ كَفَرَ الَّذِينَ قَالُوا إِنَّ اللَّـهَ هُوَ الْمَسِيحُ ابْنُ مَرْيَمَ ۖ وَقَالَ الْمَسِيحُ يَا بَنِي إِسْرَائِيلَ اعْبُدُوا اللَّـهَ رَبِّي وَرَبَّكُمْ ۖ إِنَّهُ مَن يُشْرِكْ بِاللَّـهِ فَقَدْ حَرَّمَ اللَّـهُ عَلَيْهِ الْجَنَّةَ وَمَأْوَاهُ النَّارُ ۖ وَمَا لِلظَّالِمِينَ مِنْ أَنصَارٍ ﴿٧٢﴾ لَّقَدْ كَفَرَ الَّذِينَ قَالُوا إِنَّ اللَّـهَ ثَالِثُ ثَلَاثَةٍ ۘ وَمَا مِنْ إِلَـٰهٍ إِلَّا إِلَـٰهٌ وَاحِدٌ ۚ وَإِن لَّمْ يَنتَهُوا عَمَّا يَقُولُونَ لَيَمَسَّنَّ الَّذِينَ كَفَرُوا مِنْهُمْ عَذَابٌ أَلِيمٌ ﴿٧٣﴾ أَفَلَا يَتُوبُونَ إِلَى اللَّـهِ وَيَسْتَغْفِرُونَهُ ۚ وَاللَّـهُ غَفُورٌ رَّحِيمٌ ﴿٧٤﴾ مَّا الْمَسِيحُ ابْنُ مَرْيَمَ إِلَّا رَسُولٌ قَدْ خَلَتْ مِن قَبْلِهِ الرُّسُلُ وَأُمُّهُ صِدِّيقَةٌ ۖ كَانَا يَأْكُلَانِ الطَّعَامَ ۗ انظُرْ كَيْفَ نُبَيِّنُ لَهُمُ الْآيَاتِ ثُمَّ انظُرْ أَنَّىٰ يُؤْفَكُونَ ﴿٧٥﴾ قُلْ أَتَعْبُدُونَ مِن دُونِ اللَّـهِ مَا لَا يَمْلِكُ لَكُمْ ضَرًّا وَلَا نَفْعًا ۚ وَاللَّـهُ هُوَ السَّمِيعُ الْعَلِيمُ ﴿٧٦﴾

Meaning English translation:

{They have certainly disbelieved who say, " Allah is the Messiah, the son of Mary" while the Messiah has said, "O Children of Israel, worship Allah, my Lord and your Lord." Indeed, he who associates others with Allah - Allah has forbidden him Paradise, and his refuge is the Fire. And there are not for the wrongdoers any helpers. (72) They have certainly disbelieved who say, " Allah is the third of three." And there is no god except one God. And if they do not desist from what they are saying, there will surely afflict the disbelievers among them a painful punishment. (73) So will they not repent to Allah and seek His forgiveness? And Allah is Forgiving and Merciful. (74) The Messiah, son of Mary, was not but a messenger; [other] messengers have passed on before him. And his mother was a supporter of truth. They both used to eat food. Look how We make clear to them the signs; then look how they are deluded. (75) Say, "Do you worship besides Allah that which holds for you no [power of] harm or benefit while it is Allah who is the Hearing, the Knowing?" (76)}

[Quran, chapter 5, verses 72-76]