At the same time, Allah condemns the religious groups which are still available, the Jews and the Christians, for changing the Book and He mentions that they have corrupted the Book and that they write some things with their own hand, they pen some things and say this is from Allah but it is not from Allah [see 3:78]. And likewise He condemns them for changing the religion of Allah and for innovating like Allah subhaanahu wa ta`aalaa in soorat al-Hadeed [see 57:27] condemns the Christians for inventing ar-rahbaaniyya or to be like a monk, not to get married, and to live a life away from women, marriage and alike. And likewise, Allah subhaanahu wa ta`aalaa condemns them for raising `Eesaa ibn Maryam to a status above his by claiming that he is son of Allah [see 9:30]. The Qur'aan says they have disbelieved those who say the Messiah is the son of Allah [see 5:17, 72]. And Allah subhaanahu wa ta`aalaa says that they have disbelieved those who say that Allah is one of a trinity [see 5:73].
And Allah subhaanahu wa ta`aalaa condemns them, saying that they have taken their rabbis and their priests as lords besides Allah and they have taken the Messiah the son of Mary also as a lord besides Allah and they were commanded only to worship Allah alone. This is a verse in soorat at-Taubah, the ninth soorah of the Qur'aan [see 9:31]. And the Prophet sallAllahu `alaihi wa sallam explained how they took their rabbis and priests besides Allah as lords in the sense that they obeyed them in what they knew was forbidden by Allah subhaanahu wa ta`aalaa. In other words, these rabbis and monks and priests would forbid something which was made lawful to them by Allah subhaanahu wa ta`aalaa and they would obey them in that.
Or they would make to them something lawful which was forbidden by Allah and they would obey them in that [as reported by Ahmad, at-Tirmidhee and Ibn Jareer], like for instance with the Christians and the issue of multi-marriages, having more than one wife. The Christians have forbidden this even though Allah has made it lawful for them. And, in fact, they find in their books the Prophets are mentioned having more than one wife. And likewise the Christians have made for themselves lawful to eat the flesh of swine, pig's meat, pork, and this is something which has been forbidden by the laws of Allah. So they by them obeying them in these matters they have taken them as lords besides Allah.
"And indeed, there is among them a party who alter the Scripture with their tongues so you may think it is from the Scripture, but it is not from the Scripture. And they say, 'This is from Allah', but it is not from Allah. And they speak untruth about Allah while they know." [Aal `Imraan (3):78]
"Then We sent following their footsteps [i.e. traditions] Our messengers and followed [them] with Jesus, the son of Mary, and gave him the Gospel. And We placed in the hearts of those who followed him compassion and mercy and monasticism, which they innovated; We did not prescribe it for them except [that they did so] seeking the approval of Allah. But they did not observe it with due observance. So We gave the ones who believed among them their reward, but many of them are defiantly disobedient." [Al-Hadeed (57):27]
"The Jews say, 'Ezra is the son of Allah'; and the Christians say, 'The Messiah is the son of Allah.' That is their statement from their mouths; they imitate the saying of those who disbelieved [before them]. May Allah destroy them; how they are deluded?" [At-Taubah (9):30]
"They have certainly disbelieved who say that Allah is Christ, the son of Mary. Say, 'Then who could prevent Allah at all if He intended to destroy Christ, the son of Mary, or his mother or everyone on the earth?' And to Allah belongs the dominion of the heavens and the earth and whatever is between them. He creates what He wills, and Allah is over all things competent." [Al-Maa'idah (5):17]
"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." [Al-Maa'idah (5):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." [Al-Maa'idah (5):73]
"They have taken their scholars and monks as lords besides Allah (i.e. by their obedience to them rather than to what Allah revealed), and [also] the Messiah, the son of Mary (i.e. by their worship of him in conjunction with Allah). And they were not commanded except to worship one God; there is no deity except Him. Exalted is He above whatever they associate with him." [At-Taubah (9):31]