‘grace’ in this context is a closer meaning to mercy — that is the mercy of God. Or, by God’s mercy we obtain salvation through Christ. God gives us mercy to come to him, he does not give us obedience to come to him. God’s mercy is his grace. We remain in grace by being obedient, we fall from grace (mercy) when we are disobedient. That is why we fall from grace when we follow after the Law.
we are saved by what we hear (remember preaching?) and not by what we read.