We celebrate this weekend the Solemnity of Our Lord Jesus Christ, the King of the Universe. Let me talk a little theology with you all, unpacking, albeit cursorily, what it means that Jesus is King. I won't take offense if you fall asleep while reading. Hopefully my homily will be more engaging.
When Jesus came upon this earth and then died for our sins, he offered himself to the Father. This offering to the Father obtained our salvation. Jesus then also took the fruits of this offering, or merits, theologians might say, and applied them to each of us. Thus, there is an upward movement of Christ to the Father, as well as a downward (or lateral) movement of Christ to us.
Mary, by the way, works with Jesus in that lateral movement. She assists those divine graces coming to us from the fruits of Christ's offering.
So Christ dying was just one part of the equation. We need to receive, each of us, the fruits of that death. It is possible for us to not receive the fruits; for us to reject the graces Christ won for us. To help fight against this, Jesus has established himself as King (and Mary as Queen).