Researched by the Ignaria Editorial Team · Published 2026-05-05
Fasting is one of the three disciplines Jesus assumes in the Sermon on the Mount (alongside prayer and almsgiving), and the early Church took it with corresponding seriousness. The Didache (c. 90–110 AD), the earliest surviving church manual, instructs fasting twice weekly — Wednesday and Friday — as the regular Christian practice. Tertullian (On Fasting, c. 210 AD) traced fasting all the way back to the Garden: the first divine command to Adam was a food restriction, and Adam's transgression was a failure of fasting; Tertullian therefore saw the entire penitential tradition as the human recovery of that original discipline. The tradition identifies three interlocking purposes for fasting. First, it is an act of repentance and bodily humility before God — Daniel's fast at the opening of his great prayer (Daniel 9:3) is the pattern. Second, it has ascetic power: Chrysostom and the Desert Fathers taught that fasting weakens the passions and sharpens prayer by subordinating the body's appetites to the soul's priorities. Third, Calvin (Institutes, III.20) gave it an ecclesial dimension: public fasts called by pastors in times of war, pestilence, or moral crisis are a corporate act of dependence that has marked the church in every serious period of its life. Andrew Murray captured the personal logic with characteristic precision: "Prayer is the reaching out after God and the unseen; fasting, the letting go of all that is of the seen and temporal."
What the primary sources show
"Israel, before their gathering together by Samuel on occasion of the drawing of water at Mizpeh, had sinned; but so immediately do they wash away the sin by a fast, that the peril of battle is dispersed by them simultaneously" — Tertullian illustrates fasting's immediate reconciling effect: Israel's communal fast at Mizpeh both expressed repentance and dissolved the crisis that followed from it.
"Prayer is the reaching out after God and the unseen; fasting, the letting go of all that is of the seen and temporal. Prayer needs fasting for its full growth: this is the second lesson. Prayer is the one hand with which we grasp the invisible; fasting, the other, with which we let loose and cast away the visible" — Murray's paired image: prayer and fasting as the two hands of spiritual communion with God.