An extract from "The Shape of Faith: The sign of the cross is a reminder of whose we are." by Nathan Bierma. A very informative and yet amusing article on the sign of the cross, thanks to an online friend, A. Comments in square brackets are mine.
"In the fourth century, St. John Chrysostom (apparently anticipating an American Express slogan) wrote, "never leave home without making the sign of the cross." [ hahaha! ;-) ]
"...Presumably, early Christians were taking their cues from passages in Genesis 4:15, Ezekiel 9:4, and Revelation 14:1 and 22:4 that describe a mark on the forehead as a sign of God's claim on a person. [Oh wow! Right, now that these are mentioned... ]
"...The right cross, still practiced by Eastern Orthodox believers, symbolizes how "Christ
descended from the heavens to the earth, and from the Jews (right) He passed to the Gentiles (left)," according to Pope Innocent III. In Roman Catholic practice, the left cross has become standard, showing, (in one of many interpretations) that the believer hopes to be not on Christ's left with the goats, as in Jesus' parable at the day of judgment, but on Christ's right." [Hmmm... I can understand the right cross symbolism but not the left cross symbolism. Oh! Does the writer (or whoever introduced it) meant to say that where our fingers rest is where we symbolically will want to end up?]