بسم الله الرحمن الرحيم
أَلَمْ تَرَ إِلَى الَّذِينَ تَوَلَّوْا قَوْمًا غَضِبَ اللَّهُ عَلَيْهِمْ مَا هُمْ مِنْكُمْ وَلا مِنْهُمْ وَيَحْلِفُونَ عَلَى الْكَذِبِ وَهُمْ يَعْلَمُونَ (١٤) أَعَدَّ اللَّهُ لَهُمْ عَذَابًا شَدِيدًا إِنَّهُمْ سَاءَ مَا كَانُوا يَعْمَلُونَ (١٥) اتَّخَذُوا أَيْمَانَهُمْ جُنَّةً فَصَدُّوا عَنْ سَبِيلِ اللَّهِ فَلَهُمْ عَذَابٌ مُهِينٌ (١٦)لَنْ تُغْنِيَ عَنْهُمْ أَمْوَالُهُمْ وَلا أَوْلادُهُمْ مِنَ اللَّهِ شَيْئًا أُولَئِكَ أَصْحَابُ النَّارِ هُمْ فِيهَا خَالِدُونَ (١٧)يَوْمَ يَبْعَثُهُمُ اللَّهُ جَمِيعًا فَيَحْلِفُونَ لَهُ كَمَا يَحْلِفُونَ لَكُمْ وَيَحْسَبُونَ أَنَّهُمْ عَلَى شَيْءٍ أَلا إِنَّهُمْ هُمُ الْكَاذِبُونَ (١٨)اسْتَحْوَذَ عَلَيْهِمُ الشَّيْطَانُ فَأَنْسَاهُمْ ذِكْرَ اللَّهِ أُولَئِكَ حِزْبُ الشَّيْطَانِ أَلا إِنَّ حِزْبَ الشَّيْطَانِ هُمُ الْخَاسِرُونَ ١٩
Meaning: Have you not seen who have friendship with a people with whom Allah is angry. They are neither of you nor of them. And they swear false oaths while they know.  Allah has prepared a severe punishment for them. Indeed, evil is what they used to do.  They have taken their oaths as a shield, then have prevented (people) from the way of Allah. Therefore, for them there is a humiliating punishment.  Their riches and their children will never benefit them against Allah. They are the people of the Fire. They will live there forever  (It will be) on the Day when Allah will raise all of them, and they will swear before Him as they swear before you, and will think that they have some standing. Beware that they are sheer liars.  The shaitan (Satan) has prevailed upon them, so he has made them forget the remembrance of Allah. They are the party of shaitan. Be sure that it is (the members of the) party ofShaitan that are the losers. 
لا تَجِدُ قَوْمًا يُؤْمِنُونَ بِاللَّهِ وَالْيَوْمِ الآخِرِ يُوَادُّونَ مَنْ حَادَّ اللَّهَ وَرَسُولَهُ وَلَوْ كَانُوا آبَاءَهُمْ أَوْ أَبْنَاءَهُمْ أَوْ إِخْوَانَهُمْ أَوْ عَشِيرَتَهُمْ أُولَئِكَ كَتَبَ فِي قُلُوبِهِمُ الإيمَانَ وَأَيَّدَهُمْ بِرُوحٍ مِنْهُ وَيُدْخِلُهُمْ جَنَّاتٍ تَجْرِي مِنْ تَحْتِهَا الأنْهَارُ خَالِدِينَ فِيهَا رَضِيَ اللَّهُ عَنْهُمْ وَرَضُوا عَنْهُ أُولَئِكَ حِزْبُ اللَّهِ أَلا إِنَّ حِزْبَ اللَّهِ هُمُ الْمُفْلِحُونَ (٢٢)
Meaning: You will not find those who believe in Allah and in the Hereafter having friendship with those who oppose Allah and His Messenger, even though they were their fathers or their sons or their brothers or their clan. They are such that Allah has inscribed faith on their hearts, and has helped them with a spirit from Him. And He will admit them to gardens beneath which rivers flow, wherein they will live forever. Allah is pleased with them, and they are pleased with Allah. Those are the party of Allah. Be sure that it is (the members of) the party of Allah that are the successful. 
Commentary of these verse in Ma’ariful Quran:
(Have you not seen those who have friendship with a people with whom Allah is angry? ….58:14) Allah condemns the hypocrites who secretly formed an alliance with the Jews who challenge Allah and His Apostle, while in effect they belong neither to the Muslims nor to the Jews. Consequently, Allah has prepared for them a humiliating and condign chastisement.
The difference of relationship with a believer and non-believer
It is not permissible to have a friendly intimacy with the enemies of Allah and His Messenger -whether the unbelievers are Jews, or Christians, or pagans or of any other creed. Even rationally this is not possible, because the capital asset of a believer is the love of Allah, while a non-believer relishes in opposing and challenging Him. It is not possible for a person to have sincere love and affection for someone and to love and have intimacy with the latter’s enemy.
Here ‘love’, ‘affection’ or ‘intimacy’ refers to the one coming from the heart involving intense emotional commitment (which necessarily includes having love with his way of life). This is called Muwalah or ‘intimate friendship’. This type of friendship is limited to sincere Muslims. Therefore, the Qur’anic verses on many occasions strictly prohibit Muslims from having this sort of relationship with non-Muslims. Any Muslim who has such intimate friendship with non-Muslims will be seen to fall in the circle of unbelievers.
In contra-distinction to Muwalah [intimate friendship], there is a concept of Muwasah which refers to the relationship based on sympathy, kindness and concern. It includes charitable assistance and support, business, commercial, trade dealings and economic co-operation, condolence and consolation and any well-meaning attitude of well-being and welfare. Barring unbelievers who are at war with the believers, this kind of relationship is permissible with all other non-Muslims. The paradigm of the Holy Prophet ﷺ and the noble Companions in this direction is ample testimony to this practice.
However, it is necessary to ensure that the relationship of Muwasah is not harmful to the cause of religion; it should not create laxity in ‘faith and practice’ of Islam nor should it ‘harm, hurt or injure’ other Muslims. Please see Ma’ariful Qur’an, Vol. 2/ pp 54-61: under Surah Al-’Imran: v.28-30 for a detailed account of the distinction between Muwalat [intimate friendship], Muwasat [sympathy] and Mu’amalat[dealings] or Mudarah [cordiality].
The dreadful sin of false swear
وَيَحْلِفُونَ عَلَى الْكَذِبِ (and they swear false oaths…58:14). It means they swear oaths profanely. According to some reports, this verse was revealed in connection with ‘Abdullah Ibn ‘Ubayy and ‘Abdullah Ibn Nabtal: One day the Messenger of Allah ﷺ was sitting with his noble Companions and said to them: “Soon a person will come to you whose heart will be the heart of a tyrant and who sees through the Satan’s eyes.” Soon afterwards ‘Abdullah Ibn Nabtal, the hypocrite, entered. He was blue-eyed, wheat-coloured, short-statured and skimpy-bearded. The Messenger of Allah ﷺ asked him: “Why do you and your comrades use obscene words against me?” He swore that he did not do that. Then he called his comrades and they too took this false oath. Allah told the Holy Prophet ﷺ about their lie and profane oath. [Qurtubi]