They were not under Christ in the OT. They were under the Law.
Christ is the door, and that door was opened after his death and resurrection.
dispensationalism is horrible.
Romans 11:2-5
"God hath not cast away his people which he foreknew. Wot ye not what
the scripture saith of Elias? how he maketh intercession to God against Israel, saying,
Lord, they have killed thy prophets, and digged down thine altars; and I am left alone, and they seek my life.
But what saith the answer of God unto him? I have reserved to myself seven thousand men, who have not bowed the knee to the image of Baal.
Even so then at this present time also there is a remnant according to the election of grace."
Acts 3:16-21
"But those things, which
God before had shewed by the mouth of all his prophets, that Christ should suffer, he hath so fulfilled.
Repent ye therefore, and be converted, that your sins may be blotted out, when the times of refreshing shall come from the presence of the Lord; And he shall send Jesus Christ, which before was preached unto you:
Whom the heaven must receive until the times of restitution of all things,
which God hath spoken by the mouth of all his holy prophets since the world began."
Matthew 17:11-12
"And Jesus answered and said unto them,
Elias truly shall first come, and restore all things.
But I say unto you, That Elias is come already, and they knew him not, but have done unto him whatsoever they listed. Likewise shall also the Son of man suffer of them."
Amos 9:13-15
"Behold, the days come, saith the LORD, that the plowman shall overtake the reaper, and the treader of grapes him that soweth seed; and the mountains shall drop sweet wine, and all the hills shall melt.
And I will bring again the captivity of my people of Israel, and they shall build the waste cities, and inhabit them; and they shall plant vineyards, and drink the wine thereof; they shall also make gardens, and eat the fruit of them.
And I will plant them upon their land, and they shall no more be pulled up out of their land which I have given them, saith the LORD thy God."
Luke 4:18
"The Spirit of the Lord is upon me, because he hath anointed me to preach the gospel to the poor; he hath sent me to heal the brokenhearted,
to preach deliverance to the captives, and recovering of sight to the blind, to set at liberty them that are bruised,"
Isaiah 61:1-4
"The Spirit of the Lord GOD is upon me; because the LORD hath anointed me to preach good tidings unto the meek; he hath sent me to bind up the brokenhearted, to proclaim liberty to the captives, and the opening of the prison to them that are bound;
To proclaim the acceptable year of the LORD, and the day of vengeance of our God; to comfort all that mourn;
To appoint unto them that mourn in Zion, to give unto them beauty for ashes, the oil of joy for mourning, the garment of praise for the spirit of heaviness; that they might be called trees of righteousness, the planting of the LORD, that he might be glorified.
And they shall build the old wastes, they shall raise up the former desolations, and they shall repair the waste cities, the desolations of many generations."
John 6:44-45
"No man can come to me, except the Father which hath sent me draw him: and I will raise him up at the last day.
It is written in the prophets, And they shall be all taught of God.
Every man therefore that hath heard, and hath learned of the Father, cometh unto me."