I have long been suspicious of the motives of Western Buddhists when it comes to converting or choosing to become a Buddhist or a Zen Buddhist. It is somewhat like getting a divorce after a long marriage then, in only a few weeks, finding a new partner that will somehow make up for the loss. All the while the new relationship is going on, one's mind is never without the thought of their former spouse.
In general, many Western converts to Buddhism and Zen never really get away from the religion they left behind. Zen Buddhism often becomes a new kind of Christianity free of all the troubling elements of the former religion. A secular Buddhist, for example, is really an agnostic or atheistic Protestant. Instead of asserting the sovereignty of God it is the sovereignty of human nature that is asserted by the secular Buddhist. These same Buddhists insist on man’s imperfect nature and his imperfect institutions; and maybe there is no privileged truth or privileged values. Finally, for the secular Buddhist and Zennist there is the faith to doubt for the sake of truth which never seems to come.
We never get a clear unbiased picture of what the Buddha is really saying as long as we have not completely broken our ties with our previous religion. On somewhat of a personal note, I don’t see Buddhism and modern Christianity as having much in common. But from the side of Buddhism I can see elements in the older forms of Christianity in which it appears to be moving towards a Buddhist viewpoint.