This might work if you do background checks like a daycare center would do. If not you are asking for legal trouble if one or some of the parents or babysitters have a criminal sex offender background with children.

In the Catholic Church all people who volunteer their services for the church when children are around have to complete a "Protecting God's Children" workshop and pass a background check. They also use a buddy system to make sure nobody is alone with a child.

That might be a reason that your church rejects it as well.