inward holiness in the spirit before God. And this is the reason specially why he said this, in order to show that there is nothing holy but that holiness which God produces within us.
— Martin Luther
The Eucharist is the Sacrament of Love; It signifies Love, It produces love. The Eucharist is the consummation of the whole spiritual life.
— St. Thomas Aquinas
But he immediately adds another clause, to teach us, that if anything in us tends to life, it is what the Spirit produces; for no spark of life proceeds from our flesh.