Fasting is often associated with giving up certain foods or mealtimes in order to pray, but Isaiah 58:1-14 makes it clear that fasting is more than a religious ritual. We have to fast not only from food (give up chocolate or sugar or miss a meal in order to pray, by all means), but from practices which God abhors. Thus, He tells us fasting also means ‘to loose the chains of injustice and untie the cords of the yoke, to set the oppressed free and break every yoke’ (Is 58:6), to ‘share your food with the hungry, to provide the wanderer with shelter, to clothe the naked and not turn away your own flesh and blood’ (Is 58:7), and to ‘do away with the yoke of oppression, with the pointing finger and malicious talk.’ (Is 58:9) There is a clear connection between fasting and our behaviour and treatment of other people.
Pope Francis has given useful advice for the kind of fasting God wants:
As always in the Christian life, there has to be a renunciation of the wrong and an embracing of the right. Christianity is not all about the ‘Thou shalt nots’, but there does have to be repentance and turning away from wrong things in order to walk on the narrow path of obedience which leads to life. Getting the balance is the hard part: we can either become dour, resentful, pharisaical people, or we can be over-casual, not respecting the holiness and righteousness of God. We need to fast from wrong practices but also to embrace right ones.