Is it legal to invite guest speakers to help teach about religion?
Yes, if the school district policy allows guest speakers in the classroom.
If a guest speaker is invited, care should be taken to find someone with the academic background necessary for an objective and scholarly discussion of the historical period and the religion under consideration. Faculty from local colleges and universities often make excellent guest speakers, or they can recommend others who might be appropriate for working with students in a public school setting. Religious leaders in the community may also be a resource. Remember, however, that they have commitments to their own faith. Above all else, be certain that any guest speaker understands the First Amendment guidelines for teaching about religion in public education and is clear about the academic nature of the assignment.