In a good sense, Thanksgiving is about what we do: we give thanks. In a better sense, it is about what we have to be thankful for. All the living have something for which to be thankful. In the best sense, Thanksgiving is about the God who has given us every good thing.
“Every good and perfect gift is from above, coming down from the Father of the heavenly lights, who does not change like shifting shadows.” (James 1:17). So let us give thanks in everything and at all times. God gave us these gifts, and continues to give, not just so that we have, but so that we would be thankful. One of the best gifts God gives is a heart full of thanksgiving: a heart that recognizes its need and is grateful for every thing. And that is his goal: not just to give us good things, but to make us good things.
That is the Law & Gospel: that we so profoundly do not deserve what in Christ we so abundantly have. “For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.” (John 3:16).
Give thanks for true thanksgiving, forever.