Nehemiah 12 is about the dedication of the wall.  The Israelites have completed their big project.  The re-building of the wall has now been finished and now it is time to celebrate.  When we come to major milestones and important events in our lives, God wants us to pause for a moment and celebrate.  It's good to have joy.  It's good to thank God for where He has brought us and what He has brought us through.  What do you have to celebrate today?  What are thankful to God for today?