where did the superstition of crossing your fingers come from
Crossed fingers The origin of the gesture traces back to the biblical Kingdom of Israel. Courts of Mosaic law would often render verdicts with the phrase "May God have mercy upon your soul" in order to reaffirm God's supreme authority over the law. Most judges felt that while they could pass a sentence of death upon a person, they personally did not have the authority to destroy souls and that only God had the authority to do that.[4][5][6][7][8] As a result, some judges would cross their fingers whenever they said the phrase as a result of concern for the criminal's soul as they said it as a prayer.[9][10][4][5]
Sign of the cross The sign of the cross may be made by individuals upon themselves as a form of prayer and by clergy upon others or objects as an act of blessing. The gesture of blessing is certainly related to the sign of the cross, but the two gestures developed independently after some point. In Eastern Christianity, the two gestures differ significantly. Priests and deacons are allowed to bless using the right hand, while bishops may bless simultaneously with both, the left mirroring the right. While individuals may make it at any time, clergy must make it at specific times (as in liturgies), and it is customary to make it on other occasions.