There is very little real witness a teacher can have in place that outlaws the ten commandments, muzzles religious speech, and insists on using godless curriculum. Believers must be submissive to their employers, and this loyalty to the NEA-dominated administrators in public schools would seem to force some compromise on Christian teachers. His example of participation in the government schools will tend to place his seal of approval on the system and thereby encourage weaker Christians to believe that those schools are an OK place to send their children. They can excuse their own irresponsibility by pointing to the example of the mature Christian who teaches at the school. The presence of the Christian teacher will comfort them and reinforce their tendency to take the easy road and abandon their little ones to the roaring lion of humanist education.
Christian teachers are a noble breed and they sacrifice much to serve others.
Their aim is to help the children they teach. This contributes to turning the hearts of children away from their fathers and mothers and to disrupting that channel of grace and blessing that God intends between parents and children. The traditional school model hinders the process of inter-generational biblical discipleship. And the noblest intentions do not erase a negative result, even in Christian schools. So Christians should consider cutting the rope and letting the government schools crash.