This is my little plastic jar of Holy Water. Every Orthodox church performs a great blessing of waters during the feast of Theophany (the commemoration of Jesus’ baptism in January 6) and the holy water is distributed to the congregation.
The following sermon by St. John of Shanghai and San Francisco touches on the significance of Holy Water:
On Theophany, the Day of the Lord’s Baptism, every year a great miracle is performed. The Holy Spirit, coming down upon the water, changes its natural properties. It becomes incorrupt, not spoiling, remaining transparent and fresh for many years. This Holy Water receives the grace to heal illnesses, to drive away demons and every evil power, to preserve people and their dwellings from every danger, to sanctify various objects whether for church or home use. Therefore, Orthodox Christians with reverence drink Holy Water — a great Agiasma (holy thing), as the Greeks call it.
One should always have at home enough Theophany water to last the whole year, and make use of it at every need: in cases of illness, leaving on a journey, whenever one is upset, students prior to examinations, etc. People who drink a little Holy Water daily, before eating any kind of food, do well. It strengthens the powers of our soul—if it is done with prayer and reverence, and one does not merely expect a mechanical result from it.
The idea of water with mystic powers seems like superstition to the modern mind, even to a Christian. But holy water ties into an idea central in Christianity. The work of salvation happens simultaneously and inseparably in both the spiritual and physical realm. Jesus Christ saved souls and expelled demons, and at the same time healed the sick and fed the hungry. Likewise, the grace of God can work both invisibly and through the physical form of this holy water.
Given my training, I found this a very strange and uncomfortable part of orthodoxy. There is an odd dissonance that comes with being a religious man of science. I am comfortable with the abstract ideas, the sophisticated theological arguments. But the Christian faith does not permit me to remain in this comfort. It demands that I acknowledge the sovereignty of God not just in the spiritual realm, but also on water, oil, and bread. It confronts me, not with an idealized metaphor of resurrection, but with the promise of dead flesh- my dead flesh- coming back to life.
God is the Lord both of the spiritual and material, and my little plastic jar of holy water is a small, valuable reminder of this wonderful, divine truth.