You can call out things like “Use your whole body!” to help them become involved. Or, if you see a few ‘hanging back’ you can just call out in general “Take a risk and join in!”
This should be great fun and generate lots of spontaneous energy.
Sentiment, tear-jerking, jokes, etc. are cultural weapons. On our stages, let us cry and laugh not from old frames of reference but from the sheer joy of watching human beings explore a greater beyond.