How would you answer the following argument: "Getting drunk is a sin, but gluttony is also a sin. Since the Bible doesn't tell us at what point drunkenness or gluttony is sinful, it is up to us to determine how much is too much. To completely abstain from alcohol is as ridiculous as saying you must completely abstain from food."
Now, I know from I Timothy 5:23, the Bible authorizes wine as a medicine and so it is not exactly parallel to grape juice (though that does not make it okay to drink [wine] even as a medicine (I Corinthians 8:9). I would also argue that Ephesians 5:18 condemns the process of getting drunk. But I am having a hard time finding a Biblical pattern to refute the above argument. What would be the Biblical principle(s) governing the line between eating and gluttony?
The argument assumes that drinking alcoholic beverages and eating food are exactly equivalent. In others, there is an assumption that problem is solely in the realm of quantity consumed. It assumes that one can drink alcohol at some level without harm on a daily basis. Thus, the arguer must show that casual drinking of alcohol is permitted in the New Testament. You see, I can prove from the Bible that eating is both expected and necessary to sustain life. But that fact doesn't justify overeating. However, I cannot prove that drinking alcohol is expected or necessary to sustain life. To argue that it is only wrong when it is overused skips a necessary step.
The passages that you list are covered in the article New Testament Beverages, so I won't repeat the arguments here.