For follow-up discussion and general commentary on the topic. Comments are sorted chronologically.
If you pick at every little thing that others do, you will end up with pride and self righteousness. If you thank God for forgiving you of all your sins, you will show grace and mercy to others and love them without looking for all their little faults. Do unto others as you would have them do unto you.
Drinking to much coffee or smoking or drinking or dancing or all of our other man made laws and rules are not the same as adultery, homosexuality, stealing, and judging every one a sinner who does not walk like you.
We end up with no love for God or anyone except our own rules and regulations which we have made higher than Gods laws. Pride is still the greatest of all sins as it is the one that got satan kicked out of heaven when he said, "i will be like the most high". Little i on purpose.
I will not hold people accountable to me for every tiny detail of the law. I am pretty sure God is going to judge me on how I judge others so I am pretty careful how I do that.
Sorry for the diatribe but there is just far to much of this in the church and I believe God is going to judge us for it. Like Jesus told the Pharisees, there is a better chance of a prostitute going to heaven than some of you.
But I guess you cannot show grace and mercy if you have never received it.
Thank God He has forgiven me of all my sins and I do show grace and mercy to others.
I appreciate this question and answers very much. Not just a discussion about caffeine, but about dependencies on substances which are not mentioned in the Bible. When something begins to domonate one's time, attention and money, you have crossed over into a dangerous area. No one can serve 2 masters. Substance abuse of any kind means that use of that substance has become a master in place of God. Using a substance as a coping mechanism can become a stronghold for the enemy. Justifying abuse of a substance is one of the enemy's tactics. I am speaking from experience when I say that substance abuse (whether medically addicted or not) can negatively affect relationships and distract one from God's priorities. Just something to be on guard for.