Jesus tells us that Saint Abraham, Saint Isaac and Saint Jacob are in heaven. Isaiah tells us that it is through Jesus that Israelites have thier sins forgiven. The reason God gave the Israelites the Commandments is the same reason Jesus gave Christians the Commandments. And that is to teach us how to Love God and fellow man.
The way people go to heaven (for both OT and NT people) is through the blood of Jesus, the reason people go to heaven is because they love God and love for God is accomplished through free from the will of God obedience to the will of God.
Please visit Jesus, What Must I Do To Share In Everlasting Life?
NAB LUKE 13:28
****And there will be wailing and grinding of teeth when you see Abraham, Isaac, and Jacob and all the prophets in the kingdom of God and you yourselves cast out.
NAB ISAIAH 53:4
(Isaiah to the Israelites.)
Who would believe what we have heard? To whom has the arm of the Lord been revealed? He grew up like a sapling before him, like a shoot from the parched earth; There was in him no stately bearing to make us look at him, nor appearance that would attract us to him. He was spurned and avoided by men, a man of suffering, accustomed to infirmity, One of those from whom men hide their faces, spurned, and we held him in no esteem. Yet it was our infirmities that he bore, our sufferings that he endured, While we thought of him as stricken, as one smitten by God and afflicted. But he was pierced for our offenses, crushed for our sins, Upon him was the chastisement that makes us whole, by his stripes we were healed. We had all gone astray like sheep, each following his own way; But the LORD laid upon him the guilt of us all.
NIV JOHN 14:23
Jesus replied, "If anyone loves me, he will obey my teaching. My Father will love him, and we will come to him and make our home with him. He who does not love me will not obey my teaching. These words you hear are not my own; they belong to the Father who sent me."
NAB MARK 10:17
"Good Teacher, what must I do to share in everlasting life?" Jesus answered, "Why do you call me good? No one is good but God alone. You know the commandments:
'You shall not kill;
You shall not commit adultery;
You shall not steal;
You shall not bear false witness;
You shall not defraud;
Honor your father and your mother.’"
Peace in Christ,