The gesture of crossed fingers traces back to the early Church, Christians would cross their fingers in order to invoke the power associated with theChristian cross for protection, when faced with evil. Moreover, Christians, when persecuted by the Romans, used the symbol of crossed fingers, along with the Ichthys, in order to recognize one another and assemble for worship services. In 16th century England, people continued to cross fingers or make the sign of the cross in order to ward off evil, as well as when people coughed or sneezed.
This superstition thus became popular among many early European Christian cultures. In some places, a comrade or well-wisher placed his index finger over the index finger of the person making the wish, the two fingers forming a cross. The one person makes the wish, the other empathizes and supports. Over centuries, the custom was simplified, so that a person could wish on his own, by crossing his index and middle fingers to form an X. But traces remain—two people hooking index fingers as a sign of greeting or agreement is still common in some circles today.
Charles Panati believes that the act of crossing one's fingers as a sign of luck or making a wish traces back to pre-Christian times, speculating that the cross was a symbol of unity and benign spirits dwelt at the intersection point. A wish made on a cross was a way of "anchoring" the wish at the intersection of the cross until the wish was fulfilled.