Salvation has always been by God's grace, man don't deserve anything from God.
But salvation has not always been by faith alone in that grace, apart from works (Romans 4:5). Man is only enjoying that now, during this dispensation of grace, because the nation Israel has rejected their Messiah. (Romans 11:11).
By making it so easy for all of us former gentiles to be saved, God is trying to provoke Israel to jealousy for rejecting him, recall how the Sanhedrin was gnashing their teeth at the Holy Spirit, speaking thru Stephen in Acts 7:54-58?
But after the Body of Christ is raptured into heaven, the Tribulation begins once again for the nation Israel, and the doctrine from Hebrews to Revelations will now apply.
Do you realized in those books, salvation is by faith AND works, and never by faith alone apart from works? Everyone knows where that is found in James 2, but it was also written in Hebrews, 1 John, 1 Peter, Jude, and of course Revelations.