This message ties New Year's resolutions in with baptism by describing how God makes us new people through the work of Christ. We cannot "fix" ourselves or transform on our own power. Baptism reminds us that the blood of Jesus washes away our sins. He does the work, and we trust Him to make us clean and renewed.
https://ministry-to-children.com/new-life-baptism-sermon
https://ministry-to-children.com/wp-content/uploads/2021/01/childrens-sermon-new-life-in-baptism.pdf
Law/Gospel Theme: We can make plans and goals and try to will ourselves into being “better.” But the truth is that we are powerless on our own. With the help of Christ, all things are possible. This message centers on the work that God does in us. Baptism cleanses us by the power of the Holy Spirit. We can daily return to God and be thankful for His mercy.