[jwalsh07]

Can it not be said that a teacher in a government-funded school holds the public trust?

It can be said that a public school teacher is a state actor be they biology, calculus or religion teachers.

You're not actually of a mind that religion is banned from the public square, are you?

[Condorman]

It can be said that a public school teacher is a state actor be they biology, calculus or religion teachers.

Does it stand to reason that a religion teacher would not be hired were they not of the religion they are to teach?

You're not actually of a mind that religion is banned from the public square, are you?

Of course not. Only that it is improper for the government to prefer one religion (or sect thereof) over another.