“Patience is only one faculty; earnestness the devotion of all the faculties. Earnestness is the cause of patience; it gives endurance, overcomes pain, strengthens weakness, braves dangers, sustains hope, makes light of difficulties, and lessens the sense of weariness in overcoming them.”

Source: Dictionary of Burning Words of Brilliant Writers (1895), P. 5.

Volume V, part IX, chapter III, section 52 (1860).
Modern Painters (1843-1860)

Reported in Josiah Hotchkiss Gilbert, Dictionary of Burning Words of Brilliant Writers (1895), p. 562.

Message dictated to Sanjeeva Reddy at Guruprasad (6 June 1960), as quoted in The God-Man : The Life, Journeys and Work of Meher Baba with an Interpretation of His Silence and Spiritual Teaching (1964) by Charles Benjamin Purdom, p. 353 <!-- also quoted in The Silent Master : Meher Baba, Avatar of the Age (1987), by Irwin Luck, p. 15 -->
General sources
Context: It is better to deny God, than to defy God.
Sometimes our weakness is considered strength, and we take delight in borrowed greatness.
To profess to be a lover of God and then to be dishonest to God, to the world and to himself, is unparalleled hypocrisy. Difficulties give us the opportunity to prove our greatness by overcoming them.

Original: In un periodo negativo è fondamentale non perdere mai la speranza di poter superare le difficoltà, iniziando a lavorare su sé stessi per riportare luce vitale nel profondo della propria essenza.
Source: prevale.net

Source: The Art of Loving

1830s, The Lyceum Address (1838)

Variant: The man of virtue makes the difficulty to be overcome his first business, and success only a subsequent consideration: this may be called perfect virtue.
Source: The Analects, Other chapters

[Swami Aseshananda, Glimpses of a Great Soul; a Portrait of Swami Saradananda, 43]