Answer: If we did not hear such Divre Torah in the past and do not have the means to listen to them in the present, we can read contemporary Divre Torah. If we can, we will pattern our own, original Divre Torah on the model or models that we read. If we cannot craft a D'var Torah of our own, we can read what other students of Torah have written, making sure to give credit to the person who wrote what we are quoting.
Either way, it is important that people who attend our synagogue services learn about our religious tradition and not go hungry for words of inspiration and insight. Hungry people will go elsewhere to be fed -- and the Messianics and others will be all too happy to feed them.