I find that you need lots of different activities at different levels for a diversity of ages. But I also find the class to be very fun with lots of ages. I think all of the kids benefit from it. Hope some of that helps. With multiple ages you really have to keep things simple.
Action games work well, such as relay races and usually accomodate a variety of ages.
Any crafts that you do need to be process oriented. For example instead of having the kids make a finished product to take home that is going to bore the older kids and too difficult for the younger. You can do things like put out play dough and have the kids make props to use durning the story. He had many brothers. Could you make the brothers for today's story.