"All beings are by nature Buddha, as ice by nature is water. Apart from water there is no ice; apart from beings, no Buddha." - Hakuin Zenji
Buddha nature, we are told, is universal. Buddha is not limited to one great person in history. Buddha is not a single wise teacher from the East. Sidhartha whom we call the Buddha was one who "woke up" to realize his Buddha Nature. By doing this he became an example to follow, a demonstration of what being fully human and totally alive really means. And so, followers of the Buddha's wisdom are trying to wake up to their own Buddha nature.
This is exactly my understanding of "Christ." Christ for me is not a person but a principle, a principle that was demonstrated by a Galilean prophet named Jesus. By following Jesus' wisdom I am trying to demonstrate the Christ principle within me. Christ wasn't Jesus' last name, it is a universal principle that Jesus lived out. He became Christ, or, we could say he demonstrated his innate Christ Nature. Followers of Jesus will also become, to some degree, Christ; or, we could say followers of Jesus are trying to demonstrate their Christ Nature, the Christ within.
As a Christian I can affirm, All beings are by nature Christ, as ice by nature is water... Jesus got there before us, but to serve as the example, not the exception.