If you like, use repentance as righteousness, the fear of the Lord and eschewing evil as well. Add to that, keeping the Law.
If God didn't save these unrighteous ones, why not? they were Israelites. Weren't they in the covenants? In fact, time after time, we see great numbers of them destroyed and only a remnant saved.
Before the Cross these saints had faith in God, but they didn't have any idea that Jesus Christ would offer the perfect sacrifice for our sins. IOW, they had faith but not in The Gospel that we've been given after the Cross. We see two dispensations one before and one after the Cross.
In fact, time after time, we see great numbers of them destroyed and only a remnant saved.
But we see this in Christianity today. There are large churches that don't preach The Gospel. Instead we see a mish mash of universalism and works dependent salvation.