1) Ascetic 2) One who has taken the pledge 3) Religionist 4) Religious person 5) Teetotaler 6) Teetotaling type 
• (n.) One who abstains; esp., one who abstains from the use of intoxicating liquors.
Ab·stain'er noun One who abstains; esp., one who abstains from the use of intoxicating liquors. 
[n] - practices self denial as spiritual discipline 2. [n] - a person who refrains from drinking intoxicating beverages
noun someone who practices self denial as a spiritual disciplineabstinent noun a person who refrains from drinking intoxicating beverages
a person who abstains from something regarded as improper or unhealthy, esp. the drinking of alcoholic beverages. · a person who abstains from anything.