It is because,when we r going to temple,we are actually get involved in 'koodhu pirathanai'
that means a group of devotees which has different backgrounds praying at the same place.Whereby,at home,we just pray among us,family members and friends.
Please notice that not necessary to go to the temple to get the God or Goddess blessings,according to our religion.If ones heart is true,then the God will come to him at anytime and anywhere,thats Hinduism.If we gathered some number of people at home and doing the preyers and bhajans,that called as a koodhu prathanai,so it fullfill the requirement of the individual satisfaction to get involved in public as well at temple.Thus,the positive energy will be there,around the pratthanai area.
It is scientifically proven that the spirituall,ritual of hinduism is great because once a scientist had done this experiment to a glass of water to see the magic of koodhu pirathanai from various kind of people n around the world.He actually placed a glass of water in his office at 2.30 pm and it came out in news paper says to the public that 'send your wishes and nice thoughts to the glass of water in my office' because he is researching about the power of water and its energy towards humans health.
Before the advertisement,he had actually test various types of water collected from different place,for an example,from lake,daily use water or tabed water.He use them to crystalize them and watch its shape.It looks ugly when no wishes and no good thoughts in it.So,he wants to crystalize the water after some period of time as he published in news paper on that particular day.
It is proven that,when good thoughts and wishes are focus towards the water,it becomes beautiful crystal shape as cristmas snow.So when a glass of water receieve the good energy and a human drink it.Thus he will never fall in sick because the water he drank has a great cure medicine towards our body and keep us firm.
Thats the reason of Hinduism culture,to place a glass of water in the altar,placing flowers in a bowl plus water in it and etc.
Hinduism also,has a water Goddess name Ganggai or Gangga Matha.It reflect that according to Hinduism,natures are precious for the devotee and preserve it as God or Goddess.Thats the logic reason of a indian gains abishegha theertham from temple,thulasi theertham,sanggu theertham and other kind of thertham as well.So remember to drink the theertham from the temple in any form of prasatham.
NOTICE THIS: DONT RUB UR HEAD AFTER YOU DRINK THE THEERTHAM,IT WILL BREAK THE POWER OF THE HOLY WATER AND YOU MAY NOT BE ABLE TO FEEL ITS POWER,SO JUST RUB UR HANDS FRONT AND BACK.