The Day of the Lord, the time of judgment
upon the world, cannot come until the
Rapture comes first.

Isaiah, being an Old Testament prophet,
didn't foresee the Rapture of the Church,
or even the Church itself. If Isaiah were to
speak in our time, He might say, "the Day
of the Lord is at hand and therefore, the
Rapture comes soon. A time of judgment
is coming upon the earth but the Church
will be delivered from it!"