It should go without saying, but changing God's word, even for "noble" motives, is never a good thing. Almost from the beginning, God has commanded us "You shall not add to the word which I command you, nor take from it, that you may keep the commandments of the Lord your God which I command you." (Deuteronomy 4:2). And again, in Proverbs 30:6: "Do not add to His words, Lest He rebuke you, and you be found a liar." And of course, there's the famous part of Revelation that says "For I testify to everyone who hears the words of the prophecy of this book: If anyone adds to these things, God will add to him the plagues that are written in this book; and if anyone takes away from the words of the book of this prophecy, God shall take away his part from the Book of Life, from the holy city, and from the things which are written in this book." (Revelation 22:18-19).
Now, I don't know about you, but personally, I don't want to be found a liar. I want to keep the commandments of God, and with that receive His blessings, not His wrath. Therefore, while I have to confess that getting drunk is a sin, I also have to profess that this is not the whole story. It is not ok to run around saying "the Bible says don't drink alcohol", because it doesn't. Thus, even if my motives are "clean", such as not wanting my Christian brethren to get drunk, I am actually sinning if I say "no, no alcohol, period."
Of course, there may be some wisdom in setting this standard forward as mere advice. It can be useful to set up little guardrails and personal markers in order to stay within the explicit commands of God. Thus, I believe God is pleased when we show this level of self control. Therefore, there is no sin in preaching against alcohol, so long as you are preaching it as your own advice, and not as the teaching of Scripture.
But sadly, we appear to have learned nothing over the centuries, and so just as the Pharisees taught, as doctrine, the teachings of men, so also do we import our own traditions into the faith, passing them off as if God Himself had revealed them. And teetotalism is one of many examples.
Studying through Scripture, it cannot be denied that the Bible is very permissive of alcohol. It's seen in The Law, it's seen in the Psalms, it's even seen in New Testament imagery, such as drinking wine in remembrance of Christ, who shed His blood for us. Eradicating all room for doubt, Christ Himself actually drank.
Now, Christ, first of all, is God. We're not talking half God, half man here, either. In Him dwells the fullness of Godhead bodily (Colossians 2:9). Any limit Christ had was a result of Him emptying Himself (Philippians 2:7), which in no way changed His actual divinity. God cannot be tempted to evil, nor does He Himself tempt anyone (James 1:13-14). Therefore, there is no possible way Jesus would have drunk wine, nor would He have encouraged, much less commanded, any consumption of wine, if drinking was a sin.
Furthermore, we know that at no point prior to the crucifixion did Jesus sin. That's the only reason it worked! It's penal substitutionary atonement: "For He made Him who knew no sin to be sin for us, that we might become the righteousness of God in Him." (2 Corinthians 5:21). If Jesus had known sin, He couldn't have been sin for us, He could only have been sin for Himself. But Jesus, knowing no sin, knew the Godly pleasures of alcohol.
Against this truth, teetotallers (who, in this context, I use to refer to those who condemn alcohol for others, not those who simply choose to abstain) claim that alcohol is, in effect, a brand new invention. The wine of Jesus' day was not alcoholic at all, they say. There are several problems with this, starting with the fact that if you remove alcoholic wine from the first century, you also remove it from all the verses that condemn its abuse. In 1 Timothy 3, for example, when the qualifications for a bishop and deacon are given, Paul makes sure to specify that bishops must not be given to wine, or deacons to much wine. This makes perfect sense if wine was alcoholic, but if you distinguish between wine back then and wine now, then these verses do not mean a bishop and deacon cannot drink much modern wine.
You see, then, how this argument just blows a giant hole in the teetotaller's case. It immediately becomes harder to argue against modern alcoholic beverages if you want to claim "wine" back then was non-alcoholic. Not that you can't still make the case, of course. Guns weren't invented back then, I can still make a rather compelling case against shooting random people in the face. But it's a lot easier to see a guy drinking too much wine and say "well, he's not qualified to be a deacon" than to start getting suspicious of your bishop if you happen to catch him in a canteen with an open bottle of Tropicana...
But ultimately, it's just not true. Wine and grape juice are not the same thing, nor have they ever been. This is shown from the simple fact that in the Bible, wine could get you drunk. This is why Paul exhorts us "...do not be drunk with wine, in which is dissipation; but be filled with the Spirit," (Ephesians 5:18, emphasis added). Why bother telling us not to be drunk with wine if you can't get drunk with wine? You can't get drunk with grape juice. Try it. It won't do anything more than drinking too much water.
See, not only was wine quite clearly alcoholic, but it was well recognised to be so. This is why we know Jesus not only drank, but caught flak for it: "For John came neither eating nor drinking, and they say, ‘He has a demon.’ The Son of Man came eating and drinking, and they say, ‘Look, a glutton and a winebibber, a friend of tax collectors and sinners!’ But wisdom is justified by her children.”" (Matthew 11:18-19).
So notice, John was genuinely teetotal. He famously lived on a diet of honey and locusts, so no wine for him. By contrast, Jesus "came eating and drinking", and He was accused of being a winebibber. Rather than just refute the charges, pointing out that He lived a life of Asceticism, He simply says "wisdom is justified by her children".
It would be positively asinine to call Jesus a winebibber if He demonstrably never drank that which could actually get Him drunk. Clearly, therefore, that which He drank did have that capacity. He thus instead says "wisdom is justified by her children". Being wise Himself, Jesus never got drunk. It is, however, a historical fact that He drank.
Thus, teetotallers have only one place to turn: The appeal to consequence fallacy. Although first century wine could indisputably get one drunk, and yet Scripture indisputably speaks positively of its moderate use, modern technology has amplified it a hundredfold. Heavy alcohol use has destroyed many lives, and runs rampant in our society. Thus, while it was ok in the past, it's evil now.
This, however, falls under the same category as adding to Scripture. See, God is the champion of foresight. He doesn't just change His mind, nor does He need to adapt to new information. Do you not think God knew what we would do with alcohol over the centuries? Do you imagine this new technology took God by surprise? Of course it didn't! He knew it was coming, and thus if He was going to change His alcohol policy to account for it, He'd let us know (Amos 3:7). He wouldn't leave us to guess.
Thus, the alcohol policy remains the same today as in the first century: Faith, due care, love, and moderation. If you are fully convinced in your own mind that you can drink, and you may do so without harming another or losing your self control, you may do so, and no one has the right to judge you. Now obviously, if you find a drink it's impossible to fully consume without getting drunk, then don't drink a full bottle. Getting drunk remains a sin. But drinking, in itself, is not.
So what are we to think of preachers who say otherwise? Well, we have just rebuked them, and they have been found liars. As harsh as that sounds, they have altered the word of God, and so it is their due penalty. If you find a preacher preaching on the dangers of alcohol, good for him. We need to be aware of what risks we take in order to be fully informed if we take them. But if you have a preacher who says it is a sin, that preacher either does not know His Bible, at which point he should never open his mouth on the matter, or he knows it and is lying, at which point you may as well put the devil in the pulpit.
To the latter preacher, my one message to you is it is not your job to withhold your congregation's liberties from them because you do not trust them to use them correctly. The correct use of the truth is between them and God. Your job is to give them that truth. If they abuse it, that's not your fault, but if they stumble because of your lies, that is your fault. Beware: Teachers receive stricter judgement (James 3:1). So teach the truth. Alcohol isn't sinful, drunkenness is. You say that, your hands are clean. You say otherwise, may the Lord rebuke you.