Al-Ma'idah' - 5:68

قُلْ يَا أَهْلَ الْكِتَابِ لَسْتُمْ عَلَى شَيْءٍ حَتَّىَ تُقِيمُواْ التَّوْرَاةَ وَالإِنجِيلَ وَمَا أُنزِلَ إِلَيْكُم مِّن رَّبِّكُمْ وَلَيَزِيدَنَّ كَثِيراً مِّنْهُم مَّا أُنزِلَ إِلَيْكَ مِن رَّبِّكَ طُغْيَانًا وَكُفْرًا فَلاَ تَأْسَ عَلَى الْقَوْمِ الْكَافِرِينَ
[5:68]
Say: O followers of the Book! you follow no good till you keep up the Taurat and the Injeel and that which is revealed to you from your Lord; and surely that which has been revealed to you from your Lord shall make many of them increase in inordinacy and unbelief; grieve not therefore for the unbelieving people.
Say: "O People of the Book! ye have no ground to stand upon unless ye stand fast by the Law, the Gospel, and all the revelation that has come to you from your Lord." It is the revelation that cometh to thee from thy Lord, that increaseth in most of them their obstinate rebellion and blasphemy. But sorrow thou not over (these) people without Faith.
Say O People of the Scripture! Ye have naught (of guidance) till ye observe the Torah and the Gospel and that which was revealed unto you from your Lord. That which is revealed unto thee (Muhammad) from thy Lord is certain to increase the contumacy and disbelief of many of them. But grieve not for the disbelieving folk.