In verse 110, it was said that among the people of the Book there are those who believe, yet most of them are disbelievers. Details appear in the present verse which gives a complementary profile of those who believed from among the people of the Book, and by becoming Muslims, they adopted the distinguishing hallmarks of the Faith that go to make believers the best of communities.
Soon after praising those who had embraced Islam from among the people of the Book, the text censures those of them who did not embrace Islam and insisted on retaining their stance of disbelief, not realizing that their wealth and their children will be unable to save them from the punishment of Allah and Hell shall be their eternal abode.
Verse 117 declares through a similitude that disbelievers simply waste what they spend in this worldly life, for belief in Islam is a precondition in order that such spendings be acceptable with Allah, of whatever sort they may be. The similitude stresses the fact that disbelievers inflict this injustice upon themselves when their spendings go to waste in this world and remain rewardless in the Hereafter. If they were not to wrong themselves, if they were to embrace Islam, they would have been like other Muslims who, on suffering a worldly loss, are compensated by Allah through reward and forgiveness of sins, as reported in ahadith.
Verse 118 - 120
يَا أَيُّهَا الَّذِينَ آمَنُوا لَا تَتَّخِذُوا بِطَانَةً مِّن دُونِكُمْ لَا يَأْلُونَكُمْ خَبَالًا وَدُّوا مَا عَنِتُّمْ قَدْ بَدَتِ الْبَغْضَاءُ مِنْ أَفْوَاهِهِمْ وَمَا تُخْفِي صُدُورُهُمْ أَكْبَرُ ۚ قَدْ بَيَّنَّا لَكُمُ الْآيَاتِ ۖ إِن كُنتُمْ تَعْقِلُونَ
هَا أَنتُمْ أُولَاءِ تُحِبُّونَهُمْ وَلَا يُحِبُّونَكُمْ وَتُؤْمِنُونَ بِالْكِتَابِ كُلِّهِ وَإِذَا لَقُوكُمْ قَالُوا آمَنَّا وَإِذَا خَلَوْا عَضُّوا عَلَيْكُمُ الْأَنَامِلَ مِنَ الْغَيْظِ ۚ قُلْ مُوتُوا بِغَيْظِكُمْ ۗ إِنَّ اللَّهَ عَلِيمٌ بِذَاتِ الصُّدُورِ
إِن تَمْسَسْكُمْ حَسَنَةٌ تَسُؤْهُمْ وَإِن تُصِبْكُمْ سَيِّئَةٌ يَفْرَحُوا بِهَا ۖ وَإِن تَصْبِرُوا وَتَتَّقُوا لَا يَضُرُّكُمْ كَيْدُهُمْ شَيْئًا ۗ إِنَّ اللَّهَ بِمَا يَعْمَلُونَ مُحِيطٌ
O those who believe, do not take anyone as insider but from your own selves. They would spare no effort to do you mischief. They want you to be in trouble. Malice has come out of their mouths while what is concealed in their hearts is far worse. We have made the signs clear to you, provided that you understand. 
Look, you are the ones who love them and they do not love you. And you believe in the Book, in all of it. And when they meet you, they say, 'We believe", and when they are alone they bite their finger-tips out of rage against you. Say, 'Die in your rage." Surely, Allah is All-Aware of what lies in the hearts. 
If something good happens to you, it annoys them and if something evil befalls you, they are delighted with it. And if you keep patience and fear Allah, their cunning shall not harm you at all. And Allah is All-Encompassing of what they do.