"Zen is not about doctrines or beliefs.  It’s not about worship or devotion.  Zen is not theistic, but it isn’t atheistic either, or even agnostic.  Zen simply doesn’t address the subject of God. … Trappist monk Thomas Merton says that comparing Zen and Christianity is like comparing tennis and mathematics. … I would say that practicing Zen as a Christian is like playing tennis as a mathematician.  If you’re a mathematician and you want to play tennis, you just keep on being a mathematician and you also play tennis. … If you’re a Christian and you want to practice Zen, you just keep on being a Christian and you also practice Zen. … Zen practice can be a powerful way to help us see and let go of what gets in the way of loving God and all of God’s creation and what gets in the way of opening to God’s will." 

-- Kim Boykin, Zen for Christians