The Templar with this skill who is equipped with a vial and is standing by water can call down Sikkar's blessing upon it. There are three kinds of holy water, normal holy water, water of consecration, and baptismal water. Holy water heals those who are splashed with it or drink it of good alignment, and harms those who are evil. The Templar must of course be good aligned, but the more pious the Templar, the more powerful the holy water.
Buy empty vials from the Templar Guild Shop, stand in a room with at least 1ft of water in it, and use the Blessed Water skill. You gain a holy water component that can only be used once for a spell.
However, the component can be tattooed onto your person at the sacrifice of a slot so that you can use any spell that requires this component without having to spend money or worry about using up all your holy water. Think hard before giving up your slot for a component tattoo. Component tattoos take up one slot so decide well which slot you want to give up. You will not get your slot back again unless you reincarnate. You cannot use bulk 0 slots for tattoos.