Homily by St Ignati Briachaninov: The Lord said to His Apostles about the evil spirits, “This kind can come forth by nothing, but by prayer and fasting” (Mark. 9:29). Here is a new aspect of fasting! Fasting is acceptable to God when it is preceded by the great virtue of mercy; fasting prepares a reward in heaven when it is foreign to hypocrisy and vainglory; fasting works when it is joined with another great virtue – prayer.
How does it work? It not only tames the passions in the human body, but it enters into battle with the spirits of evil, and conquers them.
St Ignaty goes on to explain in great detail how fasting works and why we must fast, and what our disposition must be. This may be the most important text on fasting you will every read! Your battle against the spirits of the air is very weak unless you understand St Ignaty’s words!