Quotes From Book " Buddha Pill " in red :

In the Nirvana sutra, the Buddha states the unreality of killing: ...." it is like the echo of a voice in the mountain valleys. The ignorant think it is a real voice, but the wise know it is not. Killing is like this. The foolish think it is real, but the Buddha knows it is not. Chinese Buddhist History, Tikhonov & Brekke, pg 196.  

How can Buddha think and say something like that? A explanation may be found in the "awakening " of Buddha in deep meditation. He reached a non-dual state ( which goes by a few names-awakening, advaita vendanta, nirvana, universal consciousness ) when the mind ceases to discern all polar opposites including good or evil.  Hence with the cessation of good/evil, he was liberated from "karma". Discernment of life and death also ceased and he was liberated from "reincarnation", there being no life and no death. It was in this state of being that Buddha can state the "unreality of killing". 

The above is not the only source that Buddhism and Zen ( Japanese Buddhism ) holds to the "unreality of killing" which serves to justify wars, violence, kamikaze suicides, etc. Here are some further examples : 

A] In the case of Zen Buddhism, its very spiritual pinnacle – the attainment of enlightened selflessness – was used to train soldiers during World War II,‘[ The soldier] must become one with his superior. He must actually become his superior. Similarly, he must become the order he receives. That is to say, his self must disappear.’ (p. 103)  Victoria, Brian (2010). A Buddhological critique of ‘Soldier-Zen’ in wartime Japan.

B} Takuan, a famous Zen master from the 1600s, wrote: ‘The uplifted sword has no will of its own, it is all emptiness. It is like a flash of lightning. The man who is about to be struck down is also of emptiness, and so is the one who wields the sword. None of them are possessed of a mind that has any substantiality. As each of them is of emptiness and has no mind, the striking man is not a man, the sword in his hands is not a sword, and the “I” who is about to be struck down is like the splitting of the spring breeze in a flash of lightning. 47 ’  In Jerryson, M. & Juergensmeyer, M. (eds), Buddhist Warfare, pp. 118– 143. New York: Oxford University Press.

Site comment : It is recommended that you should read the book " Buddha Pill " especially the chapter " The dark side of meditation " 

Lets cotrast Biblical meditation with eastern meditation & their Christian derivatives.

The outcome for King David when he meditated in Psalms 19 was his impassioned heart-cry as a bride to Christ his Groom. David opened his heart  in full faith and trust entirely to his "Husband-to-be" that Christ may search and sanctify him for marriage. "Who can understand his errors? cleanse thou me from secret faults . Keep back thy servant also from presumptuous sins ; let them not have dominion over me: then shall I be upright, and I shall be innocent from the great transgression ". This is the outcome of Biblical meditation

However, the underlying concept of Eastern meditation & their Christian derivatives are completely different. These contemplatives presume that " the world one carries about in oneself is the important thing. And the world outside takes all its grace and colour and value from within. The second belief means that what you experience through meditation is unarguably real. Put this together with the first and it makes perfect sense that you can and should allow any thoughts or feelings to arise. There is goodness and perfection within; you need only to experience it." That goodness which is presumed to be within is ultimately discovered in meditation to be that " immortal and even divine soul " which God had given at birth to every being and which shares its consciousness and is at one with the infinite universe. 

The suggestion that an immortal soul even exists was first made by Satan to Eve in Eden. The contrast that we see is that whilst King David had a cathartic cleansing experience in authentic Biblical meditation, the eastern and Christian contemplatives find that their perfection is already formed within themselves as their in-born divine immortal soul, awaiting to be discovered in meditation. 

Very soon, Jesus is coming again, this time as our Bridegroom. I invite you to meditate as King David did on Christ that God may bless us with David's experience  that we will long for our Lord Jesus Christ.

A short video to understand the workings of meditation on your brai/mind and to help you choose the best that suits your objectives

https://www.youtube.com/watch?v=MpdtnLHDViQ

Father Thomas Keating, founder of Catholic Centering Prayer

Catholic Centering Prayer and Hinduism share identical foundational philosophy on the divinity and god-hood of all humanity. 

https://www.youtube.com/watch?v=eq2U1etK9x4

Shakira sang John Lenon's " Imagine there's no Heaven... (and no Hell) " after the Pope's UN address. If he had chosen it himself, Pope Francis could not have chosen a more appropriate song for the occasion. Why ?
Well, Pope Francis held up Thomas Merton to US Congress as one to emulate to unite people and religions. Thomas Merton sees no contradiction between Buddhism and Christianity and intends to be as good a Buddhist as he can. 

The "awakening" of Buddha is described in the term "non-dual". It refers to Buddha's peak meditative state when all polar opposites disappear. When evil and good disappeared, Buddha was liberated from his "karma". When life and death vanished, Buddha was liberated from the need to "reincarnate". 

And as John Lenon sang, when there is no heaven, no hell and no religion too, man will be liberated to live as one. His source of inspiration is obvious. The Beatles were meditating TM style with Mahareshi at that time. 

The ochestration for the Pope's visits were so seamless. An appropriate song that synthesize polar opposites reflecting the "contemplative style" of Thomas Merton as an example for Congress to unite people and religions and finally, the Pope's message to "especially guard against: the simplistic reductionism which sees only good or evil; or, if you will, the righteous and sinners..to confront every form of polarization which would divide it into these two camps.

Ahh ... finally, a non-dual spiritualistic formula for world peace ! Is there anything more to fear ?

The video of Shakira at the UN. https://www.youtube.com/watch?v=8-3wIW1Rpiw

Here are the lyrics :

Imagine there's no heaven ; It's easy if you try ; No hell below us ; Above us only sky
Imagine all the people living for today. Imagine there's no countries ; It isn't hard to do ; Nothing to kill or die for; And no religion too. Imagine all the people living life in peace. You may say I'm a dreamer, but I'm not the only one; I hope some day you'll join us. And the world will be as one. Imagine no possessions; I wonder if you can; No need for greed or hunger; A brotherhood of man. Imagine all the people sharing all the world. You may say I'm a dreamer, but I'm not the only one. I hope some day you'll join us.  And the world will live as one.

30 years later Pope Francis held up Father Thomas Merton, founder of contemplative prayer and who sees no contradiction between Buddhism and Christianity as his example for unity between people and religions. 

Catholic Church's focussed agenda - unity of people and religion

The book " Buddha Pill " - A Catholic priest named Father Gabriele Amorth – appointed the Vatican’s chief exorcist in 1986 – had publicly denounced yoga at a film festival where he had been invited to introduce The Rite (a film about exorcism, starring Anthony Hopkins): ‘Practising yoga is Satanic, it leads to evil just like reading Harry Potter,’ the priest is reported as stating, to an audience of bemused film fans. Squires, N. (2011). ‘Harry Potter and yoga are evil’, says Catholic Church exorcist. Daily Telegraph, 25 November. Squires, N. (2011).