How does the conflict in this passage develop a theme?

Mrs. Linde creates a conflict by promising something she cannot give to Krogstad, which develops the theme that empty promises can destroy relationships.
Krogstad continues the conflict by choosing clearing his name over having a life with Mrs. Linde, which develops the theme that you must often choose yourself over others.
Krogstad creates a conflict by deceiving Mrs. Linde about his intentions, which develops the theme that, in love, actions speak louder than words.
Mrs. Linde resolves the conflict by committing to a new life with Krogstad, which develops the theme that new beginnings are always possible.