what is the relationship between christianity and Zen Buddhism? are there any paralel

Could Christians benefit in anything Zen Buddhism, or rather are there inspirations in zen Buddhism that could be of spiritual help to Christians.

No none.

There are no parallels. Zen Buddism rocks and Christianity is lame and stupid.
Christians could learn a lot from Zen Bhuddism and Taoism but they never will 'cos they're too closed minded. If they could understand the Tao they would dump their christian beliefs. And choir boys the world over would sigh in relief.

big different Buddhism is not religion its just org that's what i call it i like many thing in the way they think but not believe n worship Buddha because he was just a man who wanted to b something but did he sacrificed for us? did he suffer for us ? he did nothing n threes nothing to do with Christianity n too bad Pol r so blind they follow them they think if they practice yoga n meditation ins ted praying that will save them or change something for better but that's wrong or by following there macrobiotic diet that will clean there soul Pol all what they wanna do to u is changing Ur thoughts making u elements numbers all these fake religions will just dis troy Ur life Ill like in the beginning but then Ill regret it

Oddly enough the first book I read on Zen Buddhism was written by a French Catholic Monk. Since Buddhism (and Zen therefore) do not prescribe a belief in a deity, it is fundamentally a philosophy of life and can from it's own point of view be practiced by Christians or any religious person. The benefits to all people would be the benefits derived from meditation, personal reflection and readiness to "live in the moment". Looking deeper into some of the monastic practices in Christianity one finds that many of the meditative techniques are not too dissimilar to those in zen, single focused meditation, walking meditation and the repetition of a mantra type phrase or prayer (common to Korean Zen).

both are schools of beliefs that people ascribe to.
In principle, both schools advocate causes for the betterment of the human race, with very different perspective.

Parallels, yes and no. I will try to elaborate based on my limited understanding of Zen Buddhism and Christianity. Yes, both have their earthly manifestation. However, the similarities end there. One was an earthly prince who went on a pilgrimage of sorts, doing good based on moral values. The other is the physical manifestation of God in human form (bearing in mind that there is only one Trium God in the Christian faith). though He also did good in His time on earth, He was also recorded to have rebuked (the Pharisees) and caused trouble (clearing the Temple of traders).

As in terms of benefits, i am going to say: the possibility do exist. At least, for myself. Learning is a process to me. I do not discount the validity of truth or facts just because it was advocated as 'religious teachings' under any particular school. Whatever i am taught, it is an obligation on my part to Analise and assimilate what is good for me and discard teachings that would, in my view, make me a lesser man.

Of the few Zen sayings i have came across, loosely interpreted could be considered similar:

All conditioned things are impermanent. Work out your own salvation with diligence....The Buddha's last words.

And the Christian teachings:
Philippians 3:13-14
13 Brethren, I do not count myself to have apprehended; but one thing I do, forgetting those things which are behind and reaching forward to those things which are ahead, 14 I press toward the goal for the prize of the upward call of God in Christ Jesus.
As well as the rich young ruler who approached Jesus with the question about eternal life.

To my mind, the 2 are the same in their cause, instructions to the reader NOT to be so captivated by earthly possessions and lose focus of their central calling in life, salvation, enlightenment or to the Christian: Christlikeness, by 'working out your own salvation with diligence' or "press toward the goal for the prize of the upward call of God in Christ Jesus."

Granted, the basis of the statements are different as there is emphasis by one to "work out your own salvation" whereas the other(Christian) have already received salvation through acknowledging Christ as Lord an Savior and is now urged to press on toward Christ-likeness, the Christian ideal of the perfect man/woman.

So... from my perspective, yes, it may be beneficial, but not always. As a learning aid to my study and understanding of Christianity, yes. As a central reference and tenet of my personal life, not likely, as i prefer to live my life based on the Christian faith.

However, 1 person will differ from another. I infer and draw parallels from various sources but others may not think or see things from a similar perspective. And again i will emphasize:
Could Christians benefit from any teachings from Zen Buddhism? MAYBE.

As an aid to understanding, maybe. Spiritual aid, i would personally say, no. If one were to speak of spiritual matters, how would it be possible to grow spiritually in one faith while praying to a deity of another faith?