All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
We ask Allaah to grant you success. There is no doubt that you are on an important battlefront. You must increase your effort to teach this material in a way that endears it to Muslim children and that leaves an effect on non-Muslims, so that it could motivate them to enter into Islam. We thus advise you to display the best aspects of Islam, the authentic image of the personality of the Messenger of Allaah, sallallaahu ‘alayhi wa sallam, and the biographies of the rightly-guided Caliphs and the Imaams of the Muslims during your lessons.
We further advise you to be diligent in obtaining such material from Islamic countries and to use the Internet to contact universities and teaching centers, like the center attached to the King Faisal University in Saudi Arabia and other such centers. This is better than using material prepared by non-Muslims.
However, there is no religious impediment in using materials from non-Muslims, so long as the information it comprises is correct and does not include false claims that could have a negative effect on students.
Allaah Knows best.