Is ending a fast early sin?

[Matthew1344]

At my church we talk about fasting a lot. My pastor speaks about the 5 christian practices that unite all the fathers of the past are giving, praying, fasting, serving the poor, and resting.

I was curious about some things.

I am going to ask him today, but i was also curious to what you guys have to say.

Is it ok to set a time period to your fast?
Is it sin, if you don't fast for the time period you initially wanted?
Can you call a church wide fast, if you are not a prophet or apostle?
When fasting, must you abstain from all things except water?

 

[ZackF]

No it is not a sin. Some people need to end a fast early if only for health reasons. Fasting is a tool in the spiritual toolbox but cannot be used to bind a conscience.

 

[C. Matthew McMahon]

...Unless of course you make a vow to accomplish something specific in it. WCF 22.1, 5.

1. A lawful oath is a part of religious worship,awherein, upon just occasion, the person swearing solemnly calleth God to witness what he asserteth or promiseth; and to judge him according to the truth or falsehood of what he sweareth.b

a. Deut 10:20. • b. Exod 20:7; Lev 19:12; 2 Chron 6:22-23; 2 Cor 1:23.

5. A vow is of the like nature with a promissory oath, and ought to be made with the like religious care, and to be performed with the like faithfulness.a

a. Isa 19:21; Psa 61:8; 66:13-14; Eccl 5:4-6.

 

[Contra_Mundum]

What is fasting? It's devoting the time and energy you would otherwise dedicate to your personal maintenance (eating) instead to prayer. Its robbing yourself of the opportunity for physical self-concern--even reasonable self-interest--to focus exclusively on spiritual concerns.

These could be your own, having to do with matters of sin or righteousness; or having to do with a particular concern of someone else, or of the general interest. The commitment that takes one away from the food (for a season) is meant as a discipline, a reminder to self that regardless of how important eating is, "I have decided that this is more important to me."

I've heard of people "fasting" from something else, some other ordinary need or fulfillment that, like food, is replaced with the devotion of prayer.

A "rash vow" is itself sinful, and so should be repented of, not kept. So, swearing-to-God not to eat or drink until ten people join your church is neither in your power to fulfill, nor careful for those who depend on your health for their well-being, besides partaking of the nature of blasphemy (not by the swearing, but by daring the Spirit).

You may not vow/fast for something sinful; that's a sinful promise. You may not vow/fast as some kind of effort or proof of spiritual progress (monastic vows, for example; or Lent), which have no promise of divine blessing or assistance.

Making a sincere effort to fulfill one's vow/fast but failing might entail repentance, either for sinful neglect, or for promising more than you could deliver. At times, Providence intervenes to bring a premature end. Since the matter is between you and God, and he knows everything, sort out the conscience issue between you, and move on. Either begin your vow/fast again (with any appropriate reconditions), or else go on with life of ordinary discipline.

Don't allow yourself to be bullied by spiritual leaders into making vows/fasts unto some supposed end they have been shown. "God wants us to fast, so we can buy the property!"

Church leaders can call for volunteers in general to fast-and-pray on account of some particular occasion they have identified. This is not the same thing as pretending to the certainty: "God has called for this business." What are they doing in fact, other than calling on the church to make that general devotion I wrote in the first paragraph, acting as an organ of the general mind/will of the church.

Drilling down into "musts/must nots" in the matter of fasting seems to me misses the point. As if there were some mystical formula for getting it right. That completely takes the eyes off the end and purpose for the business.