In Ayahs 78 and 79 of Chapter 2 of the Holy Quran, Allah tells us about the ignorant and illiterate men of the Israelite clan who have no knowledge of religion except for the lies and vague ideas that they have created in their own minds. Such people wrongly write the scriptures from their own hands and then falsely declare that the scripture is from Allah, in order to reap materialistic worldly gains. The Ayah ends with Allah telling us that only misfortune is for such people because what they have used their hands to do and because of whatever material gain they will receive.
Thing is this is not a problem of the past- this is a recurring problem of the present too- Priests, Imams, Healers, Scholars and even the average Joe twists religion to suit his/her tastes. There have been many versions of some religious scriptures and clearly man has behind these amendments for ulterior motives.
May Allah always makes us focused and clear headed to stick to the word of the Quran and the authentic Ahadith. Ameen.
Relevant Translation below:
وَمِنۡہُمۡ أُمِّيُّونَ لَا يَعۡلَمُونَ ٱلۡكِتَـٰبَ إِلَّآ أَمَانِىَّ وَإِنۡ هُمۡ إِلَّا يَظُنُّونَ (٧٨) فَوَيۡلٌ۬ لِّلَّذِينَ يَكۡتُبُونَ ٱلۡكِتَـٰبَ بِأَيۡدِيہِمۡ ثُمَّ يَقُولُونَ هَـٰذَا مِنۡ عِندِ ٱللَّهِ لِيَشۡتَرُواْ بِهِۦ ثَمَنً۬ا قَلِيلاً۬ۖ فَوَيۡلٌ۬ لَّهُم مِّمَّا ڪَتَبَتۡ أَيۡدِيهِمۡ وَوَيۡلٌ۬ لَّهُم مِّمَّا يَكۡسِبُونَ (٧٩)
Among them are unlettered folk who know the Scripture not except from hearsay. They but guess. (78) Therefore woe be unto those who write the Scripture with their hands and then say, “This is from Allah,” that they may purchase a small gain therewith. Woe unto them for that their hands have written, and woe unto them for that they earn thereby. (79)