Receiving ...Jesus

Mark 9:37 (ESV) "Whoever receives one such child in my name receives me, and whoever receives me receives not me, but the one who sent me." (see also Matthew 18:5, Luke 9:48, John 13:20, and this )
In Jesus' day, children, particularly "other people's children" represented the lowest possible position on society's status-ladder. Jesus uses them as his example, not just in spite of this fact, but because of it!
Mark 10:14b (NIV) “Let the children come to me; do not hinder them, for to such belongs the kingdom of God." 
John 1:12 (NIV) "Yet to all who did receive him, to those who believed in his name, he gave the right to become children of God" 
Jesus makes it clear what a big deal it is to receive the "little ones": we are thus receiving him. And receiving him means our adoption as children of God!