Salvation through faith is the
Christian belief that
salvation can only be had by
faith - not by
good works, and not by
crazy shit.
"I cannot get to heaven, except through Christ. I am imperfect, have failed, and am not worthy to get to heaven."
It is called salvation through faith because the prerequisite for getting Christ to get you into Heaven is to have faith in this fact.
The opposing belief is salvation through works.