Episode 6 - Once saved, always saved. Truth?

Most believers in the Messiah have likely heard that once they are saved, nothing they can do can cause them to lose their salvation. Since salvation is of faith, and not of (good) works, no bad works can cause you to lose that which works did not cause you to gain in the first place. Is this the Truth?

How do we understand passages in Galatians and 1 Corinthians that enumerate how works of the flesh do exclude us from inheriting the Kingdom of Elohiym? What about James' claim that faith without works is dead? What about the verses in Peter than claim it would be worse for believers to come to the truth, and then backslide into sin, than before they received the Truth?

We do not refute that salvation is by grace through faith. And we don't condemn anyone who believes that they're saved by the blood of the lamb and nothing can rob them of that, in fact we mostly agree. But do we truly have faith - the kind of faith that brings about salvation? We believe this is a question every believer should contemplate daily, lest a worse thing come upon us.