Praying along with the Mass is the highest praise we can pay to God. We come for a sense of community – to attend this great family banquet, but most of all we are there to offer ourselves, whole and entire, in union with the perfect sacrifice of our savior.
There are a couple separate paths for this lesson, and if you only have younger kids you may want to focus on the first. Kids love stories, right? Your pre-Communion aged kids may appreciate a story about young Therese of Lisieux and how she absolutely longed to receive Communion. Three years (years!) before she was old enough, Therese started preparing the gift she would give to her beloved Jesus on her first Communion day.
We also have a story about Saint Tarcisuis, a 4th-century boy who gave his life defending the consecrated Hosts he was bringing to condemned Christians in prison. His belief in the Real Presence was put to the ultimate test.
The other path deals with a question of faith: the host and the wine look unchanged. How can we know that the consecration makes them really and truly the Body and Blood of Jesus? And for that, we have analogies, activities, and explanations to help your entire family to better understand.