In the Vedic religion also, the animals are allowed to be slaughtered in some sacrifice. But no religion, either Muhammadan or Hindu—I do not know in detail of your Christian religion—but they do not allow animal slaughter in the slaughterhouse. There are some particular rules and regulation. Anyway, that is a religious details.
But when India was too much addicted for animal slaughtering under the plea of Vedic sacrifice, the Lord Buddha appeared. Why? They misused the Vedic injunction. They misused the injunction of the Vedic . . .
So he, he proclaimed, "No, this animal slaughter should be stopped." He did not agree even with the Vedic injunction. Therefore Lord Buddha's preaching was not accepted. It was . . . once it was accepted, whole of India accepted. Under the king, under the Emperor Aśoka, the whole of India became Buddhist. But later on, Śaṅkarācārya appeared and he made against them, Vedāntist. So India . . . Buddhist religion from India was practically banished. So these are historical facts.
The real fact is that as soon as the natural sequence of living entity is jeopardized, at that time, non-religious principle, unnatural life, becomes prominent and people become embarrassed. At that time, the incarnation of Lord is, I mean to say, appeared. Yadā yadā hi dharmasya glānir bhavati bhārata (BG 4.7): "Whenever there is discrepancy in the natural life . . ." That I explained to you. Religion means the natural sequence of life. When there is some discrepancy in that natural sequence of life and there is artificial way of life, at that time, the Lord or His representative comes, either as incarnation or the representative of God. That is the rule. Yadā yadā hi dharmasya glānir bhavati bhārata.