He who truly wishes to believe in God must be lifted above himself, his mind, and even the whole world. For this reason, the value of faith is considered higher than the value of man. It is even higher than the value of the whole world. Therefore, the reward of faith should be higher than all of man's possessions along with the glories of this world. The reward of faith is God.
Orthodox Prayer Life: The Interior Way, p. 74, 20th century
What is it that I love when I love you? Not the beauty of a body or the comeliness of time. Nor the luster of the light pleasing to the eyes, nor the sweet melodies of all manner of songs, nor the fragrance of flowers, ointments and spices, not manna and honey, nor limbs welcome to the embrace of the flesh - I do not love these when I love my God. And yet there is a kind of light, a kind of voice, a kind of fragrance, a kind of foods, a kind of embrace, when I love my God, who is the light, voice, fragrance, food, embrace of the inner man, where there shines into the soul that which no place can contain, and there sounds forth that which time cannot end, where there is fragrance which no breeze disperses, taste which eating does not make less, and a clinging together which fulfillment does not terminate. It is this that I love when I love my God.
Confessions 10.6 in The Confessions of St. Augustine, p. 244, 5th century
Every work which does not have love as its beginning and root is nothing.
Unknown, 4th century
'The Lord your God is one Lord' (cf. Deut. 6:4), revealed in the Father, Son and Holy Spirit: in the unbegotten Father; in the Son, who is begotten eternally, timelessly and impassibly as the Logos, and who through Himself anointed that which He assumed from us and so is called Christ; and in the Holy Spirit, who also comes forth from the Father, not begotten, but proceeding. This alone is God and alone is true God, the one Lord in a Trinity of Hypostases, undivided in nature, will, glory, power, energy, and all the characteristics of divinity. Him alone shall you love and Him alone shall you worship with all your mind and with all your heart and with all your strength.
A New Testament Decalogue no. 1, Philokalia Vol. 4 edited by Palmer, Sherrard and Ware; Faber and Faber pg. 323, 14th century
The perfect peace of the holy angels lies in their love for God and their love for one another. This is also the case with all the saints from the beginning of time. Most truly therefore is it said that 'on these two commandments hang all the law and the prophets' (Matt. 22:40).
Fourth Century on Love no. 36, Philokalia Vol. 2 edited by Palmer, Sherrard and Ware; Faber and Faber pg. 104, 7th century
When a man reveres God with all his heart and with faith, he receives through God's providence the power to control anger and desire; for it is desire and anger which are the cause of all evils.
On the Character of Men no. 12, Philokalia Vol. 1 edited by Palmer, Sherrard and Ware; Faber and Faber pg. 331, 4th century
Between ourselves and the transcendent God there is a relationship of love, similar in kind to that between each of us and those other human beings dearest to us. We know other human beings through our love for them, and through theirs for us. So it is also with God.
The Orthodox Way, p. 12, 20th Century
The sign that thou lovest God, is this, that thou lovest thy fellow; and if thou hatest thy fellow, thy hatred is towards God. For it is blasphemy if thou prayest before God while thou art wroth. For thy heart also convicts thee, that in vain thou multipliest words: thy conscience rightly judges that in thy prayers thou profitest nought.
ON ADMONITION AND REPENTANCE.
But you cannot be a neighbour unless you have compassion on him; for no one can be called a neighbour unless he have healed, not killed, another. But if you wish to be called a neighbour, Christ says to you: "Go and do likewise."
Two Books of St. Ambrose, Bishop of Milan, Concerning Repentance, Chapter 11