In the parable of the wheat and tares, Who does the wheat represent? Who do the tares represent? Who is ...?

I don't think that it talks about religion at all. Religion is just a way to live a good life. What it is saying that there are good people that God has put on this earth to grow and do good deeds. There are things planted with these people that are evil and could affect the good. Instead of eliminating them at the beginning since it would be hard to tell which is which, they have to wait until harvest to separate them out. That has nothing to do with religion, nationality, race, but with deeds. You will recognize my people not by their clothing (including religion, race, or nationality) but by their deeds.