The Bible actually has a lot to say about drinking alcohol.* To be clear though, back in those days, grape juice was indeed fermented (causing it to contain alcohol), but it may not have been fermented to the alcohol levels that are reached in modern wines. Still, we can't call what was drunk in the Bible simply "grape juice," but at the same time, we can't assume that wine in Bible times was the same potency as wine that is sold today.
Alcohol, in and of itself, is not inherently sinful. It's a thing, and a thing cannot be a sin. What CAN become a sin is what we DO with the alcohol. Drunkenness and addiction to alcohol are definitely two things that a Christian must avoid. Then there's the consideration we must have for our fellow believers and our example to the world as followers of Christ.
“Each week we sit under the word of God together, opening our selves not primarily to information, but to transformation.”
Ephesians 5:18 says, "And do not get drunk with wine, for that is debauchery, but be filled with the Spirit." When too much alcohol gets in your system, your normally good judgment will become impaired (Proverbs 23:29-35). For the same reason why you shouldn't drink and drive, you shouldn't drink and try to make decisions about your words and actions. When we're not thinking clearly, we're not going to make good choices. Simple as that.
Anyway, 1 Corinthians 10:31 says, "So, whether you eat or drink, or whatever you do, do all to the glory of God." Could anyone make a logical argument that getting wasted would bring glory to God?
You still have to follow the laws, my friend, so underage drinking is NOT OK. ☺ However, when you are of legal drinking age, there is nothing in the Bible that forbids a Christian from drinking beer, wine, or any other drink containing alcohol. There are even verses that talk about alcohol in positive terms. For example, Ecclesiastes 9:7 says to "drink your wine with a merry heart." Psalm 104:14-15 says that wine is a gift from God "that makes glad the heart of men."