When, then, you make the sign of the cross on the forehead, arm yourself with a saintly boldness, and reinstall your soul in its old liberty; for you are not ignorant that the cross is a prize beyond all price.
Consider what is the price given for your ransom, and you will never more be slave to any man on earth. This reward and ransom is the cross. You should not then, carelessly make the sign on the forehead, but you should impress it on your heart with the love of a fervent faith. Nothing impure will dare to molest you on seeing the weapon, which overcometh all things.
+ St. John Chrysostom