All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
First of all, we remind the questioner that a Muslim should abide by the commandments of Allaah and the commandments of His Prophet whether he/she knows their wisdom or not. This is the reality of Islam. Allaah says (interpretation of the meaning): {It is not for a believer, man or woman, when Allaah and His Messenger have decreed a matter that they should have any option in their decision. And whoever disobeys Allaah and His Messenger, he has indeed strayed into a plain error.}[33:36]. However, this does not mean that he/she should not seek the wisdom behind the ruling or the order. Seeking wisdom could illustrate the goodness of the Islamic legislations and demonstrate that it does not contradict sound reason.
As regards the reason why it is not permitted to cremate the dead, it is because the dead must be respected in the same manner as a living person. The Prophet said: "Breaking a dead person's bone is as breaking it in his life." [Abu Daawood, Ibn Maajah and Ibn Habbaan] So if the sin of breaking the bone of a dead person is like the sin of breaking it while he is alive, then the sin of cremating it is exactly the same as the sin of burning it alive. In addition to this, burying the dead is the Sunnah that Allaah has legislated for the children of Aadam and He has not legislated that they be cremated. Allaah says (interpretation of the meaning): {Then He causes him to die, then assigns to him a grave.}[80:21].
As regards burying the dead in coffins, this is not the Sunnah of the Prophet nor was it the way of our righteous predecessors after him. They used to bury their dead without coffins. Moreover, buying coffins is wasting money without any benefit. Anyway the dead will not benefit from it and he/she will be rewarded according to his/her deeds whether he/she is buried in a coffin or otherwise.
It is disliked for women to attend the funeral. Umm 'Atiyyah said: 'We were told not to follow funerals but it was not emphasised as a prohibition.' [Al-Bukhari and Muslim] The Prophet also said: ''Allaah has cursed the women who visit the graves." [At-Tirmithi] Therefore, it is disliked for women to follow the funerals and to excessively visit the graves as they are not patient and grieve too much.
Allaah knows best.