We can see in scripture that people prepare themselves to approach God or to do thing they are called to do. Moses was told to remove his shoes. People kneel in preparation for prayer. People fast, and so on. We do this to draw to ourselves holy power, or holiness, to be purified.
Regarding those who wish to be holy the Zohar says:
“Therefore when a man wishes to be purified, he receives help from above, and the help of his Master encircles and protects him. He is then called 'holy'.”
You could say that by a person’s preparation he or she arouses the influences or powers of heaven.
The Zohar teaches about people who wish to do witchcraft and sorcery. It teaches us that “Whoever is drawn here [practicing witchcraft] becomes defiled.”
But more than that, evil practitioners do evil in order to defile themselves in preparation of spells and other such activities.
“If a man wishes to be defiled, several groups of lights of Klipot are waiting for him. They all hover about and around him. They defile him, so he is called unholy. They go before him and proclaim, Unholy, unholy, as it is written: "And shall cry, 'Unclean, unclean'" (Vayikra 17:45). They are all connected to the primordial serpent and are hidden in the deeds of the people of the world.”
“Moreover, one should be impure to cast a spell. One has to draw upon oneself that side of the unholy spirit.”
I wonder if we “draw upon” ourselves holiness, or impurity, by the small things we say and do?
When confronted with a problem, do we say a little prayer, or do we say a little curse (ie “oh XXXX”)? Which one prepared us to meet the challenge?
Jesus said we would be judged by even our idle words.
Some ancient Jews would add an oath to saying yes and no, but Jesus taught them not to do that.
Do we need to add heck (or worse) to “yes,” or “no?”
I think this is a part of holiness, and is a big problem in the lives of some, and a smaller problem is the lives of other.
[All of the Zohar references above are found HERE or The Zohar, Matt, Vol II, pg. 216]