Thomas À Kempis said this quote

Remain tranquil and prepare to bear still greater trials. All is not lost even though you be troubled oftener or tempted more grievously. You are a man, not God. You are flesh, not an angel. How can you possibly expect to remain always in the same state of virtue when the angels in heaven and the first man in paradise failed to do so? I am He Who rescues the afflicted and brings to My divinity those who know their own weakness.