Caffeine is an addictive substance. It is also a stimulant. There are many side effects produced by caffeine. The drug caffeine is legal, however that does not necessarily make it all right to abuse.
The very first time I fasted (going without food and/or calories/caffeine for a period of time for a spiritual purpose) I knew I was addicted to caffeine and I did not need it. I thank God that He revealed that to me. Drinks such as Sprite, decaf cokes and coffee, kool aid, some root beers, and water became my drinks of choice.
I know that this world has a habit of drinking caffeine. Please read some of the following links and what they have to say about the drug called caffeine. Consuming too much is not a good thing.
God's Word teaches a lot on keeping the body pure and sober. Read my paper on Smoking for more scriptures. Although the Bible wasn't written in the days of coffee and cappuccino, it still applies; and with some research, we can see how God has tried to keep us from consuming too much of harmful substances such as caffeine.
Titus 2:6 "Young men likewise exhort to be sober minded."
The word "sober" means this in the Greek language:
4993. sophroneo, so-fron-eh'-o; from G4998; to be of sound mind, i.e. sane, (fig.) moderate:--be in right mind, be sober (minded), soberly.
