When we fast, the commitment we make to God — what we abstain from, the nature of it, our expectations, and the length of time — is our own fast. But we are not inventing from nothing. There are fasts in the Bible with concrete instructions: the abstinence, the purpose, the length, and the result.
The three patterns
Absolute Fast
No water and no food for three days. Paul went three days without sight, and neither did eat nor drink. This is the most severe fast in Scripture and the one most often attempted carelessly. It should be short, rare, and never undertaken without medical wisdom and spiritual covering.
Partial Fast
Vegetables and water only. Daniel and the three Hebrew boys refused the king's meat and wine and asked for pulse and water instead. This is the most sustainable fast for most people and the one we teach first to anyone who has never fasted.
Partial Fast
No pleasant bread (pastries) for three full weeks.
Normal Fast
No food during the fast window; water and juice included. This is what Jesus did in the wilderness and what most Scripture means when it simply says fasting. For our movement this is the primary recurring rhythm.
If the full length is too much
A completed fast is worth more than an abandoned three-day one. Faithfulness matters more than severity.
And there is a fourth category worth naming even though it is not on the list above: the fast from something that is not food. Media. Sweets. Caffeine. Spending. A pleasure or a habit that has more of your attention than it should. Scripture's definition — food, pleasures, or normal daily activities — leaves that door wide open, and for some people it is the harder and more honest fast.