Every word should be in ones vocabulary if possible... but making a list of "loaded" religious words to watch out for might be interesting.
Start with "creation".
It doesn't apply only to the Biblical fantasy. It can also be used in it's believable form meaning one has made or built something, i.e., "I will show you my creation," and "This creation is part of a series I'm working on."
Every atheist should know that the Greek and Latin words Theos and Deus descend from the Proto-Indo-European root word *dyeu- meaning "to shine." The word Germanic word Tiu is equivelant to Theos or Deus. These word are part of a family of words from which the names of many deities descend: Zeus, Iou/Iov/Iovis/Jovis/Jove, Zeu pater (Father Zeus), Iuppiter or Jupiter (also Father Jove), Tyr (or Tiu, from which we get Tiu's day or Tuesday).
Theos is technically "the shining one", sometimes "the shining father".
The English word God descends from the Goth word guda from proto-Germanic guthan meaning "invoked". The word was invented by Ulfilas in the fourth century as a replacement for theos in the New Testament and Elohiym in the Old Testament and in contrast to Jehovah, a Hebrew verb meaning existing converted into a proper name meaning "the existing one."
The inventor believed that Jesus was the only begotten Son of the unbegotten Father. Instead of translating theos to tiu, the honest Germanic equivalent, he took the verb for "invoked" and converted it into a proper name, Guda, "the begotten one" in contrast to Jehovah, "the unbegotten one".
An atheist isn't a person without [belief in] God, they are a person without [belief in] deity. Whenever possible I choose to use the word deity instead of God because God is a proper name associated with fourth century and later Christianity and I would like to make it clear that I an without belief in any deity, not just the one most of my associates believe in.
If a friend asks, "Do you believe in God?"
I usually reply, "No, I don't believe in God or any other deity."
Or, "What church do you attend?"
"I am an atheist. I do not believe in any deity, including the modern Christian deity called God."
By wording things this way I am able to point out that my friend doesn't believe in most of the deities either, so we have a lot in common.
Perhaps it would be just as effective to use these religious words and phrases in a negative context. We sometimes say, "I didn't know you were going to turn this into an Inquisition!" The perception of the word inquisition is negative, implying a disgusting action based on vindictiveness and arrogance rather than facts or evidence.
"He's trying to turn his selfish agenda into a crusade."
"You can either sit around and pray it for it, or get up and take action to make it happen."
"I'm not about to wait around for miracles, I'm going to do something about it."
First Stupidity Theorem: The probability of predicting correctly in total
ignorance is zero.
Second Stupidity Theorem: The only thing you can learn is something you
Third Stupidity Theorem: You can't tell a man something he doesn't
understand and expect him to make use of it.
I am unsure of the true origins of these, but they seem to be attributable to a certain Dr. Wayne Batteau, of whom there is scarce information. However, these ideas were extensively expanded on by the late, great Robert Anton Wilson (also intimately involved with Discordian philosophy, Operation MindFuck etc.). [link 1][link 2]
This a wonderful word that is not used anywhere nearly enough.