Have the class bring in two balloons each. Bring in a helium tank and fill the balloons up and tie a string on the ends. On the balloons, have them write the name of a person that needs to be saved. Take them outside and let them go. Tell them by doing this, they can use it as a way of giving the person up to God in prayer. If your church has very small tracts or cards you can attach those to the string.