"A healthy mind resides in a healthy body".
The above saying illustrates the significance of the fact that a pure and  a  serene mind   rests   only   in   a   healthy   body, devoid  of  any  contents, which may be conducive to excitement or tension. A   natural   and   vegetarian   diet   or   way of life, accentuated with  gradual and consistent doses of peace and tranquility, besides being coupled with a sense of  non-violence and an attitude of well-being   towards all, raises the soul to a stage of oneness and solitude with the universe, which is the crux of all religions. Not  a  single religious  doctrine is found on the earth which advocates torture to animals leave aside their slaughter. A  person  having  religious  instincts  would tremble at the thought of harming any living being,  not to  speak  of  consuming  their flesh.
"Be merciful  to  animals and all living objects, as the lord has been merciful to us." - says Chaitanya Mahaprabhu.Chaitanya Mahaprabhu was the first saint to extol with reverence, vegetarianism 
in Bengal. He  had  experienced  the impact of vegetarianism on human mind and intellect. 
Dayanand Saraswati of  Arya  Samaj  has  gone a step further in his denouncing the traits   of   eating meat  and other non-vegetarian food. He terms the persons advocating  meat-eating as  devils, goes to  the extent of denouncing, that it is a sin even to accept food from the hands of a drunkard or a meat eater.
Continuing the sermonizing of vegetarianism by the Hindu epics and  saints, the message given by 'Manu-Smriti', is quite poignant. 
It says that - "One   who   kill animals for satisfying their needs,   will   not  get peace in this world or even thereafter".
Mahabharata, the famous religious epic has passages to  the   effect   that those, who kill animals and consume their flesh are no good, that.  monsters or cannibals. When  it  is   not   in the control of humans to give life to anyone, it goes without saying that they do not, as well, command  any  right  to 
take away any life.
Mahabharata further states on the topic, that  a  person   abiding   strictly   to   a vegetarian   way  of  life, is sacred than a person performing Ashwamegh Yagya for over hundred years.
Continuing   its   dissertation, the above  treatise on Indian religion, incites them who consume flesh in   order   to increase their own flesh, as sinners of the   first order. The quote of Atharva Veda is amply relevant :
"Those   who   eat   raw   or   cooked   meat, those who destroy the young ones of various species, shall themselves be destroyed."
Hinduism is not the sole religion advocating vegetarianism.
The   Holy   Bible   is full   of   sermons to the effect. Lord Jesus always preached humans   to   develop   a   feeling   of  love for ones fraternity and all of the living creatures. The following enlightened words of Lord Jesus, are relevant :
"I  have   come to end sacrifice and festivals of blood and if you do not stop eating and offering meat, than the anger of God will not lessen towards you."
Lord   Jesus says further - for that which be fillets the sons of men befalleth the beasts. Even one thing befalleth them ; as the one death the other; yea, they have all one breath, so that a man hath no pre-eminence above a beast.'  Jesus  always desired  people  to  eat  food  that  grows  from  the  earth.  Christianity  does  not believe that animals are for killing. 
Bible says  'thou shall not kill.'  Christianity placed   great emphasis on the peaceful   co-existence  of   man   and beast. This is the single religion, which laid maximum stress on love and compassion and advocated that the path  to heaven is  made  easy  through  love   and non-violence, rather than worshipping Christ himself.
Islam is not   behind, in preaching that non-violence is the essence of all religion. In Islam religion, Allah says :
"Man   has   no right to kill animals  and he who does so, will be accountable for his action on the day of judgment." 
Allah had  made  all living beings and has provided everyone with food. And the food for humans is in the form of vegetables and fruits. It is the will of Allah  that man  eats  only what is meant for him. Allah loves all - Jannat and Zameen,  Man and animals. So  fear God and do destroy nature as Allah sees everything and he will be punished who destroys Allah's creation.
The   very   foundation  of  Jain religion   are  the  pillars of non-violence and compassion. Non-violence is termed as the Greatest Religion of all religions. The various   discourses  by  Lord Mahavira,  last Trithankar of Jainism are filled with the milk of kindness overflowing towards the welfare of all the species on earth.
Do not unto others, what we will not have done unto us. - says Lord Mahavira.
Live and let live.
All   humanity  is  encouraged  to follow this tenet and influence others to follow suit, in   the   process   striving   for   a   life of peace and harmony devoid of any violence, on any living beings.
Buddhism is another strictly disciplined religion, the corner - stone of which is - Total Non-violence. The followers of Buddhism are bound to non-violence  and astutely avoid eating meat. Buddhist scriptures say :
When   everyone   fears   death, we   should not hasten that terror in animals by killing them. When even man fears death, we should treat animal as our equals.
Killing   animal  in  Buddhism is considered a sin (Adharma) while saving a life is religion (Dharma).
Sikhs are  of the  belief that non-vegetarianism destroys the essence of Dharma (religion),  Karma (action),   Kirtan (prayer)  and Balidan (sacrifice). Sikh religion is  of   the   strong  conviction that how can human being attain peace, when the food   which   he   eats is   procured   amidst  immense suffering on the part of an animal.
Zoroastrians treat fire  as  sacred and  as  such,  consider cooking of meat sinful. They stress on animal protection and regard slaughter-houses as dens for sinful activities.
"He  whose   hands   are   stained with the blood of animal has no right to pray to God." says the scriptures of Zoroastrians.
Religion has seem man through since time immemorial. Religion has a  place  in  a mans' life, which is   of   much more significance   to   him, than  any other human aspect or discipline. In   spite   of   this fact   and   the  vital religious belief, which human   have, animals  are  being slaughtered and their flesh sold and consumed, without even a slightest thought or any from of restraint.
It is time for people to decide whether they want to reap the fruits of religion. We need  to   revitalize  our   spirits with  a new enlightenment and to understand the love of God, we need to develop an urge to dwell deep into our holy scriptures.
The followers of Tao, the scriptures say - If you like - you shall be killed." 
Shinto religion lays on protection and love for animals. It is said that he who has mercy, lives long. So  protect  and save the animals, insects and other creatures of God.
Just imagine  how  every  one trying  to misuse the name of religion for their own selfish ends.
A  missionary   was  walking  somewhere   in Africa, when he heard the ominous padding  of  a  lion  behind  him. "Oh Lord,'  prayed  the missionary,  'grant in the goodness that the lion walking behind me is a good Christian   lion. And then, in the silence that followed, the missionary heard the lion praying too : Oh Lord,' he prayed, "We thank thee for the food that we are about to receive."