Forsake our selves and works…

In our approach to God, we must carry with us ourselves and all our works, as a perpetual sacrifice to God; and in the Presence of God, we must forsake ourselves and all our works, and, dying in love, go forth from all creatureliness into the superessential richness of God: there we shall possess God in an eternal death to ourselves.
— Blessed John Ruysbroeck (1293-1381)

This is true fasting…

The essence and power of abstinence is not in refraining from food, but in expelling from the heart every remembrance of evil and other such things. That is true fasting, and what – above all else – the Lord demands.
— Saint Leo of Optina (1768-1822)

Observe abstinence…

As long as the flesh is in full health, let us observe abstinence at all times and in every place. When it has been tamed (which I do not suppose is possible this side of the grave), then let us hide our accomplishment.
— Saint John Climacus (c. 525-606)

Seek the simplest…

Seek the simplest in all things, in food, clothing, without being ashamed of poverty. For a great part of the world lives in poverty. Do not say, “I am the son of a rich man. It is shameful for me to be in poverty.” Christ, your Heavenly Father, Who gave birth to you in the baptistery, is not in worldly riches. Rather he walked in poverty and had nowhere to lay His head.
— Saint Gennadius of Constantinople (Fifth Century)