The “wisdom of trials” and the “cause of ordeals” – ‘Abdu’l-Baha explains

Consequently the Most Great Wisdom has ordained that the fire of tests shall rage and the rushing torrent of ordeals sweep tumultuously from the Mountain of Revelation, so that the untruthful may become distinguished from the truthful, the unrighteous be known from the righteous, the worshipper of self become separated from the worshipper of God, the good fruit be set apart from the evil fruit, the signs of light become manifest and the gloom of darkness be dispelled, the nightingale of trustworthiness sing the melody of love and the raven of oppression croak the discordant notes of error; the fertile soil become green and verdant and the barren ground produce its thorns and thistles; the attracted ones to the Breath of ABHA become firm and the follower of passion and desire turn away. This is the wisdom of trials and this is the cause of ordeals. (‘Abdu’l-Baha, from a Tablet, Star of the West, vol. 1. No. 3, April 28, 1910)