It was based on Luke 18:15-17
People were also bringing babies to Jesus for him to place his hands on them. When the disciples saw this, they rebuked them. But Jesus called the children to him and said, ‘Let the little children come to me, and do not hinder them, for the kingdom of God belongs to such as these. Truly I tell you, anyone who will not receive the kingdom of God like a little child will never enter it.’I considered the relevance of this to four categories of children:
i. our own children if we have them
ii. children in our church
iii. children in society
iv. children on the margins: the unborn, orphans, street children, trafficked, handicapped, …
Here is an edited version of the talk.
The quote about Bob Pierce, founder of World Vision, is from here.