Why do some people have extremist opionions towards alcohol?

I was born in Egypt in a Christian family where my mom was like a super religious person which to be honest annoyed me, now I am an Atheist and I live here in the US and I am studying to be an engineer. My mom used to think that drinking any alcohol even just a half cup of beer on occasions like new year’s eve and such is bad and will make you go to that place she believes in called hell. Also in Egypt it is mostly Muslims and all of them were like gosh super extremists towards alcohol and if you tell one of them you drank a glass of beer on New Year eve they will be rude to you and call you an infidel and might try to harm you. More over even Christian church people like priests in Egypt tell people on New Year eve that if they celebrate by drinking just a very small amount of beer (not drunk) and they die at that moment they will go to hell which sounded very extremist to me. Personally I think drinking like a glass of beer or wine on occasions or from time to time is good and relaxing as long a person doesn’t get drunk. Also I think sometimes if you are in a restaurant with like your partner or wife or girlfriend and you drink a glass of wine it would be pretty romantic, I am not saying get drunk at all. So why in the world are some people that extremist? I just don’t get it. Do such people have had bad life before or what? Why do they act like that? Is it cultural issues or what?Any opinions? Thanks a lot