[Children] have pure hearts. They have spiritual faces. The effect of the divine teachings is manifest in the perfect purity of their hearts. That is why Christ has addressed the world, saying, “Except ye be converted, and become as little children, ye shall not enter into the kingdom of heaven”—that is, men must become pure in heart to know God. The hearts of all children are of the utmost purity. They are mirrors upon which no dust has fallen. – ‘Abdu’l-Bahá, The Promulgation of Universal Peace