Another easy unit study you could do on Passover comes from the Easy Fun School site. If I were doing this, I would probably study it alongside the lapbook using the lapbook for visual and tactile reinforcement and the EFS study as the "meat" . And, I would probably allow a week to do the activities between other school subjects.
So, those are just a couple of resources to get your creative juices flowing in anticipation for the upcoming holiday. Of course, these resources are for kids. If you've never looked into the meaning of the Passover as it relates to your Christian faith, then I would highly recommend seeing if there's a group putting on a Seder in your area. I've attended presentations put on by Jews for Jesus in the past and was tremendously blessed by them.