I want to ask about the Jama'ah Tabligh. They are translating Qur'an and Hadith according to their own understanding in order to prove that their work is from Quran and Hadith. Is this not a great sin for a Jama'ah that is known to be a religious Jama'ah?

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

The Tablighi group is a Dawah group that has an apparent impact on the field of Dawah- and like any other Islamic group, it has advantages and disadvantages. So, it is incumbent on the Muslim to follow a moderate approach when criticizing it as the knowledgeable people do whose ultimate aim is to reach the truth.

Hence, one should accept from them all that is supported by evidence from the Qur'an and the Sunnah and reject anything that is not backed by evidence. But this rejection should be through advice and kindness. Ibn Katheer narrated that Qatada said: "No Muslim should meet his fellow Muslim except with the intention of advising him and never cheating him."

As for explaining the Qur'an or the Hadith without the appropriate knowledge or guidance, no doubt that it is a great sin and it is telling lies about Allah. Allah says: "And follow not (O man i.e., say not, or do not or witness not, etc.) that of which you have no knowledge (e.g. one's saying: "I have seen," while in fact he has not seen, or "I have heard," while he has not heard). Verily! The hearing, and the sight, and the heart, of each of those you will be questioned (by Allâh). (Al-Isra 17:36)

The duty of the Muslim is to advise his fellow brother when he sees him fall in similar things that contradict Islam. But this is not peculiar to Tablighi group alone. All the modern Islamic groups have some shortcomings which should be clarified to them whenever possible.

Allah knows best.