(claiming all Christians believe in the rapture and that "scripture interprets scripture"):

A two second Google search will tell you that many Christians, if not most, don't believe in the rapture and don't consider it Biblical.

And they are then not Christian ........... there are certain common beliefs to be considered within orthodoxy ........ the rapture is one of them ....... non-belief would put them outside orthodoxy and make them not christian .......

So scripture has not interpreted scripture.

YUP ......... hence the heresies pointed out earlier ........ and those that preach them .... as scripture points out ...........