Why is Vegetarianism Important in Spiritual Matters?

An excerpt from Revelations of Ramala-from a chapter called The Importance of Correct Eating [This is a channeled work from the UK]
So far we have not discussed the question of what you should, or should not, eat. Each of you will have to decide according to your own consciousness how you should change your eating habits. What would be right for one would be wrong for another, and in this lecture I can do no more than point out a few guidelines. If you wish to raise the vibration of your bodies, you should eat only the finest foods, the foods of the highest vibrations, which are to be found mainly in the fruit kingdom —the fruits, nuts and berries which exist in profusion upon your planet. Therefore it is desirable, and note that I say only desirable, that spiritual man should become a strict vegetarian, that he should, eat only the fruits of the Earth.
…Man does not need to eat the flesh of animals. All life is sacred.
…Animals feel pain just as Man does. They experience fear just as Man does, and the emotions of animals which are killed are held within their bodies. The vibration of fear is a coarsening vibration, and when Man consumes the flesh of animals he is partaking of that vibration. Furthermore, all the diseases of an animal and the polluted food it has consumed are contained within its flesh, hence when Man eats of that flesh he is partaking those diseases and of that pollution. So, from the food aspect, the flesh of animals is the lowest of vibrations, and if Man is to walk the spiritual path he should avoid it at all costs for it will degrade his body spiritually.
…Man should be able to live from the fruits of the trees and bushes of the Earth. Of course I appreciate that it is not always possible to live entirely on fruit for, depending upon your position on the globe, at some times of the year fruit is just not obtainable.
… you should become vegetarian gradually as well… with the whole process perhaps taking a year to eighteen months. …Those of you who possess psychic powers will find yourselves becoming more psychic.
…When you have stopped eating the flesh of animals you will then be faced with a choice of eating vegetables and fruit. So as to get the maximum benefit I must say here that it is important that whenever possible you eat only raw foods, foods which are uncooked; for when he cooks, Man destroys. Cooking may make food taste nicer. Cooking may blend various ingredients into a succulent dish to appease Man's jaded tastes but, as I said when I began this lecture, the whole purpose and importance of eating food is to sustain your bodies, not to gratify your lower selves. If you eat only raw food you will find that not only will you eat less, but you will eat better. You will have a greater supply of the necessary vitamins and nutriments for your bodies. You will find that you eat less because you need less, and you will find that your bodies become lighter and finer.