“”People from the OT were covered when they kept their covenant.””
They are covered by Christ by their faith in Him who was yet to come as God Incarnate .
The OT prefigures Christ-who is God Incarnate .Thus, those who believed in him are saved since “Jesus Christ is the same yesterday, today, and forever. Heb 13.8”
Typology shows the OT is prefigured in the OT and revealed in the NT this very clear...
Old and New Testament Parallels of God the Father and God the Son
Exodus 3:14 - God says “I AM who I AM” - John 8:58 - Jesus says “Before Abraham was, I AM” in reference to Himself.
Deut. 4:2; 12:32 - the Lord God commands that we not add or take away from His word - Rev. 22:18-19 - Jesus so commands us not to add or take away from His word.
Deut. 32:39; 1 Sam. 2:6 - the Lord kills and makes alive again and raises up - John 5:21 - the Son raises and gives life.
Deut. 32:39 - neither is there any that can deliver out of God’s hand - John 10:28 - nor shall any pluck out of Jesus’ hand.
Deut. 32:43 - rejoice, ye heavens, with Him, and let all the angels of God worship Him - Heb. 1:6 - the “Him” is Jesus the Son.
2 Sam. 22:3 - God is the horn of salvation - Luke 1:68-69 - Jesus is the horn of salvation.
Psalm 19:7 - the law of the Lord is perfect - Gal. 6:2 - fulfill the law of Christ.
Psalm 24:10 - the Lord is the King of glory - 1 Cor. 2:8 - Jesus is the Lord of glory.
Psalm 45:7 - Therefore God, your God, has anointed you. God calls someone else God. This someone else is His eternally begotten Son - Heb. 1:9 - Therefore God, your God, has anointed you. cf. Heb. 1:8, 10.
Psalm 62:12 - the Lord God renders to each according to his work - Matt. 16:27; Rev. 22:12 - Jesus so renders to each according to his work.
Psalm 71:5 - the Lord God is our hope - 1 Tim. 1:1 - the Lord Jesus Christ who is our hope.
Psalm 89:27 – I will make him the first-born, the highest (“elyon” which refers to God) of the kings of the earth - John 18:36-27 – Jesus is this first-born king.
Psalm 97:9 - the Lord God is above all - John 3:31 - Jesus is above all.
Psalms 110:1 - the Lord (Yahweh) said to my Lord - Jesus = Yhwh - Acts 2:34-36 - God has made Jesus both Lord and Christ.
Psalm 148:1-2 - the angels worship the Lord God - Heb. 1:6 - the angels worship Jesus. Only God is worshiped.
Prov. 3:12 - who the Lord loves He corrects - Rev. 3:19 - who Jesus loves He corrects.
Isaiah 7:14 - a virgin will bear a Son named Emmanuel which means “God is with us” - Matt. 1:23 - this Son is Jesus Christ, God in the flesh.
Isaiah 9:6 - the child to be born shall be called Wonderful Counselor, Mighty God, Everlasting Father, Prince of Peace.
Isaiah 25:8 - God swallows up death in victory - 2 Tim. 1:10 - Jesus abolishes death and brings life and immortality.
Isaiah 40:8 - the Word of God shall stand forever - Matt. 24:35 - the Words of Jesus shall not pass away.
Isaiah 42:8 - God gives His glory to no other - John 17:5; Heb. 1:3 - yet Jesus has the same glory as the Father.
Isaiah 43:14 - the Lord God is redeemer - Titus 2:14 - Jesus is the redeemer.
Isaiah 44:6 - the Lord God is the first and the last - Rev. 1:17; 2:8; 22:13 - Jesus is the first and the last.
Isaiah 45:19 - I, the Lord God, did not speak in secret - John 18:20 - Jesus said “I have said nothing secretly.”
Isaiah 45:23 - to God, every knee shall bow and every tongue swear. Phil. 2:10-11 - at Jesus’ name every knee should bow and tongue confess.
Isaiah 48:17 - God is the Holy One - Acts 3:14 - Jesus is the Holy One.
Isaiah 60:19 - God is everlasting light - Revelation 21:23 - Jesus the Lamb is eternal light.
Jer. 17:10 - the Lord searches the hearts and repays us according to our deeds - Rev. 2:23 - Jesus searches the hearts and repays us according to our deeds.
Ezek. 1:26-28; Daniel 7:9 - God’s glorious appearance - Rev. 1:13-16 - Jesus’ glorious appearance.
Ezek. 34:11-31 - God the Father is the shepherd of the flock - John 10:7-29 - Jesus is the shepherd of the flock.
Ezek. 34:16 - God seeks to save that which was lost - Luke 19:10 - Jesus seeks to save that which was lost.
Ezek. 34:17 - God judges between cattle, rams and goats - Matt. 25:32 - Jesus judges and separates the goats from the sheep.
Ezek. 43:2 - God’s voice was like a noise of many waters - Rev. 1:15 - Jesus’ voice was like the sound of many waters.
Dan. 2:47 - the Lord is the God of gods and the Lord of Lords - Rev. 17:14 - Jesus the Lamb is the Lord of Lords.
From Scripturcatholic
OT and revealed in the NT this very clear =(should say) OT revealed in the NT is very clear