If he could not realize the condition of old age, he would not know that he was young. He would not know the difference between young and old without experiencing the old. Unless you have passed through the state of infancy, how would you know this was an infant beside you?
If there were no wrong, how would you recognize the right?
If it were not for sin, how would you appreciate virtue?
If evil deeds were unknown, how could you commend good actions?
If sickness did not exist, how would you understand health?
Evil is nonexistent; it is the absence of good. Sickness is the loss of health; poverty, the lack of riches. When wealth disappears, you are poor; you look within the treasure box but find nothing there. Without knowledge there is ignorance; therefore, ignorance is simply the lack of knowledge.
`Abdu'l-Bahá: The Promulgation of Universal Peace P.296