The church has always had signs. One of the most important signs of the church is the cross. In the early days of the church, new Christians were signed with the cross and told that the cross was an invisible tattoo (many people in the Roman era wore tattoos symbolizing their vocation). The vocation of the one wearing the invisible cross was to follow Jesus, even to death. Another powerful biblical symbol is ashes, which symbolize repentance. These two symbols, cross and ashes, mark the beginning of Lent and signal a time of intense spiritual reflection and renewal. The cross and ashes order our Lenten spirituality and compel us to spiritual attention.
-Robert E. Webber, Rediscovering the Christian Feasts: A Study in the Services of the Christian Year (Peabody, MA: Hendrickson, 1998), 42, 43.