How can I delete selected faces? I am making this house. But you see the highlighted faces in my door?



I don't know where they came from. I tried to delete them by pressing X and then choosing faces  but it doesn't do anything..
It looks like you tried to extrude the doors inwards. This leaves the edges in between the two doors, and there are now duplicate faces there. There also appears to be duplicate faces at the bottom of the doors.

Try going to vertex select mode and use box select (B) in wireframe mode to select all of the verticies in the area. Then you can delete them.