William Law wrote,
Who is the greatest saint in the world? It is not he who prays most or fasts most; it is not he who gives most alms or is most imminent for temperance, chastity, or justice; but it is he who is always thankful to God, who wills everything that God wills, who receives everything as an instance of God’s goodness and has a heart that is always ready to praise God for it.
Renovation of the Heart by Dallas Willard, page 141.