I think you're missing my point. My point is that all these saints in the OT were *saints,* but were not sinless. Whether you want to call them "born again" or not isn't the issue--that language is not even used in the Bible with respect to these people!
So let's just keep to the biblical language itself for the time being, to avoid confusion. These OT figures were not sinless, even though we would both agree they were saints. But being in the OT era, under the Law, they did *not yet have eternal life.* And so they struggled against sin, and could not obtain, in this struggle, eternal life. They could only prevail in righteousness against their inborn sin. They could not yet inherit eternal life.
So the idea of a "struggle" is something all reborn saints of God have, OT and NT. The only difference I'm talking about is the struggle OT saints had in overcoming their own personal sin with the accompanying inability to achieve eternal life. That had to come *after* Christ went to the cross. Agreed?