In reference to Mathew 18
The child placed by Jesus is beside Him to serve as a sign of the Kingdom of Heaven. So the child (about whom we know nothing except that he or she was little and lowly in status) is only to be the object of attention, care or veneration insofar as that is inherent in being a sign of the Kingdom of God. Child Theology starts with Jesus and asks what light children throw on God, the Father, Son and Holy Spirit and His way of doing things in His world (that is, the Kingdom of Heaven). This light immediately exposes the way the disciples are thinking and behaving, and their fundamental misjudgement of Jesus and the Kingdom. Put simply, if not crudely, Jesus was telling them that they had got the Kingdom of Heaven all wrong! It wasn’t just that they were a bit off course: they were on completely the wrong track. Child Theology seeks always to have the child placed by Jesus in the midst of conversations and reflections, but it is concerned with every aspect of God’s mission, and involves the whole community of God. It will lead us all to see that in welcoming children we welcome Jesus, and the One who sent Him.
From: Introducing Child Theology
Theological Foundations for Holistic Child Development
KEITH J. WHITE