Yesterday the pastor at my church used this example: he used to walk to and from elementary school. In the window of other houses, he'd see white handprints on green paper. It was a sign that if he ever needed help, he could go to that house. If he caused problems with other kids, a mom would come out of those houses and discipline him - always under the watchful eye of the 'white hand'.
I, as the oldest of nine, speak kid really really well. So when I'm on the playground or at the store and a stranger kid talks to me, I'll talk back. If they are bored, I smile at them. I have learned to be careful - you can't initiate it, and you always play with or talk to them in the sight of their mom, but kids generally realize it's OK to trust me. Today at Costco, the cutest little boy was talking to me, under the watchful eye of his big sister. When he left, the gentleman behind me and the woman across the aisle all smiled and said "bye, it was nice to meet you, have a good day bud", and other variations. For a brief second, several strangers were brought together for the protection of a child, all loving his bright little face and questions.
From the white hand elementary school parents back when my pastor was a kid to the young boy in Costco today, kids have a tendency to bring all of us together and to make us forget our differences. Maybe that's why we need to be like a little child to enter the kingdom of heaven - a child has no judgement, no fear - just a curious and loving trust.