In the Bible, the apostle Paul wrote in 2 Corinthians 5:20,
We are therefore Christ's ambassadors, as though God were making His appeal through us. We implore you on Christ's behalf, be reconciled to God.
Our movement of campus ministries finds its identity in this passage. Each of us who takes on the identity of “Christian” becomes Christ’s ambassador – or christou apostoloi in Greek, which we shorten to the first letters “Chi” and “Alpha” or XA.