First Corinthians 6:12 declares, “'Everything is permissible for me'—but not everything is beneficial. 'Everything is permissible for me'—but I will not be mastered by anything.” The Bible nowhere mentions caffeine, so the subject of caffeine addiction is not directly addressed in the Bible. All that can be done is take biblical principles that apply to being addicted to anything, and then apply those truths to caffeine addiction. First Corinthians 6:12 is likely the most applicable scripture. While the context is dealing with sexual immorality, Paul’s words clearly go beyond sexual immorality when he says, “I will not be mastered by anything.”
Similar to gluttony, caffeine addiction is something that Christians are often hypocritical about. Christians are quick to condemn addiction to alcohol and tobacco, but tend to ignore other more “socially acceptable” addictions such as over-eating and caffeine. Alcohol clearly can have more dangerous effects on behavior and can be harmful to health when abused. Tobacco is harmful to health in even small quantities. In comparison, caffeine might not seem so bad, but “it’s not as bad as…” is not something Christians should live by. Rather, Christians should live by “Is it right? Is it honoring to God?”
Caffeine, in reasonable quantities, is neither overly harmful to health nor addicting. Caffeine, in excessive quantities, is both harmful to heath and addicting. Is it wrong to have a cup of coffee in the morning to help yourself wake up? No, of course not. Is it wrong to be so hopelessly dependent on coffee that you cannot function in the morning until you have had your cup(s) of coffee? According to 1 Corinthians 6:12, the answer has to be yes. We should not be addicted to anything. We should not allow ourselves to become mastered/controlled/enslaved by anything. This surely includes caffeine. When consumed in moderation, caffeine is not a sin. When one is addicted to and dependent on caffeine, that is when it becomes a spiritual issue, and a sin that needs to be overcome.