Holy water has a double meaning of reminding us of our baptism as well as a symbol of spiritual cleansing. Holy water is said to have great power over the devil as the devil cannot stand this “clean” water, since he is entirely unclean for all eternity. It is a reminder of the water that flowed out of Christ’s side, which is a symbol of Baptism, and brings to mind the day of the devil’s defeat (Christ’s crucifixion).
It is an ancient custom to have what are called “holy water stoups” or “holy water fonts” on the walls of a home. They are elaborate or simple cups that hold holy water, which can then be used to bless oneself throughout the day.
It is especially helpful to have them at the doors that lead outside the house as well as in the bedrooms of family members. That way we keep ourselves always fixed on Christ and remind ourselves to remain pure. It also keeps the holy water handy when needed to ward off any influence of the Evil One.