[xAzerothx]

Antichrist -
1. a particular personage or power, variously identified or explained, who is conceived of as appearing in the world as the principal antagonist of Christ.
2. (sometimes lowercase) an opponent of Christ; a person or power antagonistic to Christ.
3. (often lowercase) a disbeliever in Christ.
4. (often lowercase) a false Christ.

Atheist -
a person who denies or disbelieves the existence of a supreme being or beings.