This is another authoritative statement made by the great sage Nārada. Those who kill animals and give them unnecessary pain-as people do in slaughterhouses-will be killed in a similar way in the next life and in many lives to come. One can never be excused from such an offense. If one kills many thousands of animals in a professional way so that other people can purchase the meat to eat, one must be ready to be killed in a similar way in his next life and in life after life. There are many rascals who violate their own religious principles. According to Judeo-Christian scriptures, it is clearly said, “Thou shalt not kill.” Nonetheless, giving all kinds of excuses, even the heads of religions indulge in killing animals while trying to pass as saintly persons. This mockery and hypocrisy in human society bring about unlimited calamities; therefore occasionally there are great wars. Masses of such people go out onto battlefields and kill themselves. Presently they have discovered the atomic bomb, which is simply awaiting wholesale destruction. If people want to be saved from the killing business life after life, they must take to Kṛṣṇa or God consciousness and cease sinful activity.
Ref >> Srila Prabhupada Vani.