SHAFAQNA (Shia International News Association) – It is narrated from Imam Reza (AS) who described the reasons for burying a dead body and some of these are outlined below.
1. To respect the dead person; because if the dead body is not buried then it will stink. If the body is left in wild, the body’s feature will change and the animals will eat it, this is a disrespect to the dead person and his family as no one wants this to happen to their loved ones.
2. The dead body is a carrier of viruses and bacteries which are dangerous to the public.
3. People will be bothered by the stink of the dead body.
4. If a dead body is not buried this will cause distress to the family and friends of the dead person but will please his enemies .
The question may come to mind that why not burn the dead bodies instead of burying them? It must be said that burying a dead body with special rituals has many wise reasons behind it and the most important reason is paying respect to the dead person. Imam Sadiq (AS) said: Respecting a dead person is the same as a living one .
 Beharul Anwaar, Vo. 75, Page 46.
 Alkafi, Vol. 7, Page 228.