St. John Chrysostom: On calling God "Father"

 How exceedingly great is God's love for mankind! What words are adequate to give thanks to God who gives us so many good things? Examine, my beloved, the worthlessness of your and my nature. Think about what we are related to - earth, soil, clay, bricks, dust. For since we were made out of earth, we dissolve back into earth after death. So after considering all this, be amazed at the unfathomable richness of God's great goodness toward us. For you an earthen creature have been told to call Him, the heavenly One, Father - the mortal addressing the Immortal, the corruptible addressing the Incorruptible, the ephemeral addressing the Eternal!

+St. John Chrysostom, from Homily 3 On living in accordance with God.

St. John Cassian: On the Prayer "Thy will be done..."

 "Thy will be done on earth as it is in heaven." There cannot be a greater prayer than to desire that earthly things should deserve to equal heavenly ones. For what does it mean to say: "Thy will be done on earth as it is in heaven," if not that human beings should be like angels and that, just as God's will is fulfilled by them in heaven, so also all those who are on earth should do not their own but His will? No one will really be able to say this but him who believes that God regulates all things that are seen, whether fortunate or unfortunate, for the sake of our well-being, and that He is more provident and careful with regard to the salvation and interests of those who are His own than we are for ourselves.

+St. John Cassian, from The Conferences, conference 9 On Prayer XX.1

St. Macarius the Great: Thy will be done...

For why else is it written: "Thy will be done also on earth as in heaven" (Mt 6:10)? It is in order that, as the angels in heaven live together in accord with each other in the greatest unanimity, in peace and love, and there is no pride or envy there but they communicate in mutual love and sincerity, so in the same way the brethren should be among themselves.
+ St. Macarius the Great of Egypt, from The Fifty Spiritual Homilies and the Great Letter, homily 3, #1.