To look at Christianity from Zen is really saying to look at Christianity from the perspective of intuition, the sense of which is more about the act of coming to direct knowledge without reasoning or inferring.
The Zennist would hope the Christian to see intuition as direct contact with the absolute spirit in which even the subject and the object disappear into a transcendent singularity. Explained another way, intuition is the sudden leap from flesh to spirit in which the ineffable presence of spirit is realized. This is also an epiphany if not also Zen’s satori.
Zen’s view, I assume, will not sit well with contemporary Christians who are overly consumed with literalizing the Bible. Their understanding of religion has to come through the human senses and also imagination without which they think not to have religion. This of course is where Christianity and Buddhism differ. Buddhism has an implicit prohibition towards literalizing its religion. In other words, it is against making direct intuition palatable for the senses, especially for the imagination.
It is unfortunate that the message of Christianity has to be sold to those people who are overly attached to the flesh and their imagination. Like with Zen, it is only when the Christian fully understands what spirit is about that progress can be made.
Yes, spirit and flesh are antithetical to each other just as in Buddhism the unconditioned and conditioned are antithetical. The very crucifixion of Jesus on the cross is nothing more than the total and absolute transcendence of the flesh. Spirit is incarnated in the flesh but is not of the flesh. It is through the crucifixion that the spirit is resurrected transcending the man of flesh. In this wise, Zen Buddhism and Christianity are very much the same.