Yes, that is what Scripture teaches.
But, what we also see is that revelation is progressive, so we have to now understand how men were saved back then.
It is very simple: God judges men and their fate is determined based on one thing which is consistent throughout Scripture and the Ages, and that would be man's response to the revelation they have been provided with.
So long story short, your ancestors, those who were born into a time before the Mystery of the Gospel was revealed, were held accountable for the revelation they did have.
First, we have the internal witness of God:
Romans 1:18-19
King James Version (KJV)
18 For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who hold the truth in unrighteousness;
19 Because that which may be known of God is manifest in them; for God hath shewed it unto them.
Romans 2:14-15
King James Version (KJV)
14 For when the Gentiles, which have not the law, do by nature the things contained in the law, these, having not the law, are a law unto themselves:
15 Which shew the work of the law written in their hearts, their conscience also bearing witness, and their thoughts the mean while accusing or else excusing one another)
Paul makes it clear that this revelation alone denies any excuse on behalf of men to disobey...
Romans 1:20
King James Version (KJV)
20 For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead; so that they are without excuse:
Secondly, we have the Testimony of Creation:
Romans 1:20
King James Version (KJV)
20 For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead; so that they are without excuse:
This is not just a reference to nature, I believe, but, we consider all aspects of creation and that which we encounter there. I have often wondered at the mind of the atheist, who can look upon the newborn and see a product of electro-chemical process and chance.
Lastly, we have direct revelation, and it is to this that we owe a critical understanding of the progressive nature of the Redemptive Plan.
If we simply acknowledge one basic truth, that the Gospel of Jesus Christ was a mystery not revealed in prior Ages, then we have less trouble actually understanding Progressive Revelation. While we know the Gospel of Christ can be seen as promised throughout Scripture, we have to keep in mind that men of those days did not understand it as we, born again believers, do.
So don't fret too much over your ancestors, Tom. If they were obedient to the revelation provided to them, then their fate was just as that of the faithful we read about in the Old Testament. They would have received a designation of Just, and their transgressions would be redeemed at the Cross, and at that time, they would be made perfect/complete in regards to remission of sins.
It is a common misconception that one must hear the Gospel to be saved, but, we look at Paul's statements here and see Gentiles, who did not even have the Hebrew Scriptures or the Law...said to be in obedience to the Law of God. And that is because God revealed it to them through those two means Paul speaks of.
God bless.