Child
A child is a young boy or girl in the care of parents, older than a suckling or an infant, but not yet an adolescent. "Children" are sometimes used as a name for a large group of descendants of one person, such as the Children of Israel, or even all human beings as the Children of Men. A child represents innocence and charity, where innocence is the willingness to be led, and charity is love. This is why Jesus blessed them and suggested that we all become like children in order to enter heaven.
Zechariah 12:9-10
9
It will happen in that day, that I will seek to destroy all the nations that come against Jerusalem.
10
I will pour on the house of David, and on the inhabitants of Jerusalem, the spirit of grace and of supplication; and they will look to me whom they have pierced; and they shall mourn for him, as one mourns for his only son, and will grieve bitterly for him, as one grieves for his firstborn.
