It is estimated that 80-90 percent of children from Christian families attend public schools. One argument that I hear is "I want my children to be the salt and light of the school; I want them to be missionaries."
Is a 5, 8, or 12 year old student old enough to be a missionary? Sure, there are children in mission fields all over the world with their parents. If you send your young, impressionable child off to school alone, will they share the gospel with their non-Christian friends, or will they hide their Christianity to "fit in"
One last question......How do you know your children are the missionaries in class? Is it possible that other children who don't come from a Christian family are the missionaries? Perhaps they are "ministering" to your child far more than your child is ministering to them.
God Bless and have a great weekend!