“From long experience I have learned that there is nothing like holy water to put devils to flight and prevent them from coming back again. They also flee from the Cross, but return; so holy water must have great virtue. For my own part, whenever I take it, my soul feels a particular and most notable consolation.” —St. Teresa of Avila Can Creator comment on this quote from Teresa of Avila, its meaning, and its veracity? https://www.getfed.com/8-ways-to-use-holy-water-5699

This is actually a deeper insight than most would perceive. What she is noting is that from her intuitive understanding, holy water has greater benefit than simply having a Cross in proximity to the person as worn on a necklace or in the room environment where it is visible and within reach. This is because of the ingestion or the direct contact and absorption of the energy directly within the person. It is a function of energy that it obeys many criteria. The energy of consciousness is present everywhere at once but it impinges on what it touches in many cases and when the energy of divine consciousness impinges on the water and the water is then taken into the body, or put on the body directly, it can more powerfully influence the recipient than simply having a Cross within sight or worn on a necklace. The water molecules themselves will take on special energy as a consequence and this can have healthful benefits in addition that will not come from the proximity of a Cross. There will be the imparting of a special positive benefit to the novel organisms within the water if it is from an appropriate natural source. These organisms benefit the body greatly and when imbued with divine energy will be all the more effective and long-lived to carry out this function. This will be less true today because much water used for such blessings will not be directly from lakes and rivers and natural springs as was more true in the earlier era of this saint. The other major point of difference is the intentions held by the person in their expectations. The Cross is thought of more typically for blessings, for protection, whereas holy water for general well-being and the intentions of the humans involved in the ritual are all-important because we must follow human intention always very closely and cannot deviate, and in fact many times are limited because humans have a very selective view of something and a very diminished expectation of benefit, and this will correspondingly limit what we can offer. So the quotation from St. Teresa is wholly accurate and only lacking a mechanistic explanation.