[swordsman]

Yes God has always brought salvation in EVERY dispensation ( except one) by grace through faith.

( I REALLY dislike it when people say that, I believe that it is a weak statement, a cop out.)

Yes salvation has been by grace through faith.

But faith in what?

What God said you needed to do to be saved.

Build a boat, keep the commandments, believe I am going to make a great nation from your offspring, love your brother, have faith in what Christ did and receive the faith of Christ, do not
take the mark etc...

PS: Adam was not saved by faith, he did not need faith. Faith is hope in something you do not see, Adam walked with God, talked with Him, even tried to hide from Him in the garden. No faith needed there.