I have recently been playing with silk dye and resist to engage worshippers in creating art in worship. However, silk dye and resist is not very kid-friendly in a multi-generational worship setting. To get a similar effect, you can also use white glue and water color paints.
This activity particular works for a church retreat or over a few Sundays. With each step, you can have worshippers reflecting on a particular biblical story or reflection question. Depending on what fabric you use, you will get a different effect. You can use linen, cotton, or canvas. The glue and paint will react slightly differently on each fabric so you will want to experiment.
For easy use, I cut out canvas squares and put them in embroidery hoops. This makes it easy for people to manipulate. I prefer to use 1 oz. glue bottles because they are easier to use, especially for the little ones. Have them draw words or images on the canvas.
Set them out to dry. It usually takes 24 hours for them to dry. For ones that have quite a bit of glue on them, it will take longer. I had less than a day to wait for them to dry, so I sped up the process by wiping off some of the glue with a clean paint brush and drying them with a hair dryer. When they dry, the image becomes translucent.
I love this technique because I like the idea of something being unclear and then revealed when the paint is coated over it. I like keeping worshippers guessing on what will happen next. I use water color because you want the paint to seep into the fabric and the glue can resist water color the best.
Again, reflecting on any scripture or question you want, I had worshippers walk around tables and randomly paint over any of the hoops.
As the hoops are painted, you can see the images more clearly.
The theme for this particular church retreat I led was “Guide My Feet,” so I stacked the dry hoops in the shape of foot prints in the middle of the worship space. Worshippers can then see that over time, collectively we created an art piece for worship.
Still Waters 
So cool! Question: do you give people a set time, like 10 seconds, 30 seconds, something else, to apply some paint to each hoop before asking them to move on to another hoop? I’m tentatively planning a week-long churchwide day camp (evening camp?) next summer, and this looks like a great idea for one evening! The idea behind the camp is to give folks a chance to experience a week of camp-like activities for a week without having to take a week off from work to do so. Six or seven days of 2 hour programming, including dinner, art, worship, music… have you ever tried something like that?
So I did this activity towards the end of the worship/keynote time where afterwards they were transitioning into their small group times. So I didn’t manage their time, I simply let them roam and paint how many they wanted and for how long they wanted . . . mostly because I wanted it to be playful and not too serious. But you certainly could regulate their time if you wanted to.
Thanks! I’ll let you know how it goes if this scheme of mine comes to pass! 🙂