When Jesus places a child in the midst of his disciples, he is letting them know that the debate they were having about who should be first is finished. In saying, "Whoever receives one child such as this in my name, receives me; and whoever receives me, receives not me but the One who sent me," Jesus was placing great importance in those seen as the least of all.
Children were seen, as the least of all in the time of Jesus. In placing the child front and center Jesus is showing how important it is to care for the most vulnerable and innocent of all. This gospel passage is a call for us all to accept and serve those who are marginalized.
This gospel is a call to be selfless, and recognize the divine Spirit in all of us. When we strive to embody these values, we not only honor the teachings of those who came before us but also pave the way for a more compassionate and just world.
At the end of every Mass in my parish we are dismissed, with the following “The Mass has ended let us go in peace to love and serve the Lord.” That is not a suggestion, it is a mandate. When we help care for, love, and serve others, we are the hands and feet of Jesus. He is the only one we need to put first.