What is the benefit of holy water? What is the evidence for this? If we really believed this why wouldn’t we have every material thing we have blessed or treated as a sacramental? In other words why would we only bestow these benefits on some things and not others?
I personally use Holy Water everyday. Both in the morning and just before bed. You do know you can have a Priest come to your house and bless it. Some Churches bless cars. Personally I use as many sacramentals as I can!
The blessing formula said by the priest says holy water refreshes the new life received at baptism. It’s a sacramental that refreshes and reminds us of Baptism, helps protect against evil and helps to cleanse venial sin. St Teresa of Avila said the Devil flees from holy water quicker than from anything else.
Jesus answered and said to her, “Everyone who drinks this water will be thirsty again;
but whoever drinks the water I shall give will never thirst; the water I shall give will become in him a spring of water welling up to eternal life.” John 4:13-14
Holy water is this water that Jesus gives. It comes to us in baptism and continually wells up to eternal life in us.
Holy water is a sign of this water, something that renews and refreshes us.
1668 Sacramentals are instituted for the sanctification of certain ministries of the Church, certain states of life, a great variety of circumstances in Christian life, and the use of many things helpful to man. In accordance with bishops’ pastoral decisions, they can also respond to the needs, culture, and special history of the Christian people of a particular region or time. They always include a prayer, often accompanied by a specific sign, such as the laying on of hands, the sign of the cross, or the sprinkling of holy water (which recalls Baptism).
1670 Sacramentals do not confer the grace of the Holy Spirit in the way that the sacraments do, but by the Church’s prayer, they prepare us to receive grace and dispose us to cooperate with it. "For well-disposed members of the faithful, the liturgy of the sacraments and sacramentals sanctifies almost every event of their lives with the divine grace which flows from the Paschal mystery of the Passion, Death, and Resurrection of Christ. From this source all sacraments and sacramentals draw their power. There is scarcely any proper use of material things which cannot be thus directed toward the sanctification of men and the praise of God."176