Use the time when you are with your volunteers, either before or after the service or ministry, to experience spiritual practices together—this will serve them in the moment and also give them practical things that they can do on their own time in the future. One option is Lectio Divina (Latin for “sacred word”), which is described in detail here.
Set aside 10 to 20 minutes to lead your volunteers through this spiritual practice as a group. Choose a narrative like John 5:1-9, where Jesus invites Peter to walk on the water.