Why St. Pius X allowed little children to receive Holy Communion
Children have a special place in the heart of Jesus Christ and model for us how to have a pure trust in our Heavenly Father. In a certain sense, children are already united to God when they are little. They have not been corrupted by the world and do not know the temptations of sin. It was Pius X’s hope that by allowing little children to receive Holy Communion, they would maintain that baptismal innocence into their adult lives and stay close to Jesus.
Thus his desire to give them the chance to receive Holy Communion as often as they could, keeping them united to Jesus, who would hold them tight to his heart.