On April 17, 1912, Abdu'l-Baha again spoke at the home of Mr. and Mrs. Edward Kinney. He used the changes taking place outside to illustrate the point that he wanted to make. Here are two paragraphs from his talk:
"The world has become a new world. The darkness of night which has enveloped humanity is passing. A new day has dawned. Divine susceptibilities and heavenly capacities are developing in human souls under the training of the Sun of Truth. The capacities of souls are different. Their conditions are various. For example, certain minerals come from the stony regions of the earth. All are minerals, all are produced by the same sun, but one remains a stone while another develops the capacity of a glittering gem or jewel. From one plot of land tulips and hyacinths grow; from another, thorns and thistles. Each plot receives the bounty of the sunshine, but the capacity to receive it is not the same. Therefore, it is requisite that we must develop capacity and divine susceptibility in order that the merciful bounty of the Sun of Truth intended for this 24 age and time in which we are living may reflect from us as light from pure crystals.
The bounties of the Blessed Perfection are infinite. We must endeavor to increase our capacity daily, to strengthen and enlarge our capabilities for receiving them, to become as perfect mirrors. The more polished and clean the mirror, the more effulgent is its reflection of the lights of the Sun of Truth. Be like a well-cultivated garden wherein the roses and variegated flowers of heaven are growing in fragrance and beauty. It is my hope that your hearts may become as ready ground, carefully tilled and prepared, upon which the divine showers of the bounties of the Blessed Perfection may descend and the zephyrs of this divine springtime may blow with quickening breath. Then will the garden of your hearts bring forth its flowers of delightful fragrance to refresh the nostril of the heavenly Gardener. Let your hearts reflect the glories of the Sun of Truth in their many colors to gladden the eye of the divine Cultivator Who has nourished them. Day by day become more closely attracted in order that the love of God may illumine all those with whom you come in contact. Be as one spirit, one soul, leaves of one tree, flowers of one garden, waves of one ocean. "
The above paragraphs can be found in the book The Promulgation of Universal Peace.