God, by his grace, made deals where individuals and nations have hope, not only in this world, but for eternity. God promised the biblical patriarchs that if they believed in and obeyed God, they and their peoples would be saved. God promises Christians that if they believe and obey Christ, they and their households will be saved (It is expected that the head of the house would teach scripture to his own home and that they would be saved also).
During my own life I read the Old Testament several times, not cover to cover necessarily, but sometimes in completion and other times by topical studying. It appeared to be a great narrative of mankind's origins and history, with the law, songs and prophecy thrown in, many of which I failed to understand! I won't say that I got nothing out of the Old Testament, but it didn't minister to me as it should have!
While I was driving on a long trip one day I was thinking of the story of Abraham and his willingness to sacrifice Isaac, his son, to God on the hilltop. As you may remember, God substituted a goat kid in the place of Abraham and Isaac was spared. I said to myself "That's all about Jesus!" From then on whenever I read scripture, I ask "What's that got to do with Jesus?" With that question the Old Testament, which was a mystery became crystal clear! Everything is about Jesus!
Modern churches have the luxury of having both testaments. We not only read about Jesus, but we read the words of Jesus, often printed in red. We now have "page 2" as Paul Harvey always said! Immediately upon the death and resurrection of Jesus, people became his disciples. They believed in and followed Jesus. The early church (assembly of his disciples), called Nazarenes and later Christians, was founded in the mid-first century, before the New Testament was written and became canon (officially accepted as divinely inspired scripture by the early church).
The New Testament refers often to "scripture". If Matthew through Revelation had yet to be written, let alone accepted, then what does "scripture" mean in the New Testament (NT)? Obviously, "scripture" is Judeo "scripture" and is the Old Testament (OT). What does the NT say about scripture (i.e., the OT)? Let's see just a few of many verses:
2 Timothy 3:16 "All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness:"
2 Timothy 3:15 "And that from a child thou hast known the holy scriptures, which are able to make thee wise unto salvation through faith which is in Christ Jesus."
The OT is inspired by God, and has many uses, foremost being "instruction in righteousness". The OT tells how to get saved and that it's all about faith in Jesus. Yes, the OT is all about salvation and Jesus! Should modern Christians read, know and love the OT? Yes, Jesus confirms the necessity!
Matthew 22:29 "Jesus answered and said unto them, Ye do err, not knowing the scriptures, nor the power of God."
Mark 12:10 (Jesus) "And have ye not read this scripture; The stone which the builders rejected is become the head of the corner:"
The OT is not only about the law, but the law fulfilled. Metaphorically, the OT is the excitement of the coming championship game, but the NT is the joy after winning the game. Jesus is that joy as can be seen from:
Mark 14:49 "I was daily with you in the temple teaching, and ye took me not: but the scriptures must be fulfilled."
Luke 24:26 "Ought not Christ to have suffered these things, and to enter into his glory? 27 And beginning at Moses and all the prophets, he expounded unto them in all the scriptures the things concerning himself."
Back to my story of my eyes being opened by the story of Abraham. The Holy Spirit opened my eyes to the OT. I saw that the entire text pointed toward Jesus, prophesied Jesus and the stories paralleled Jesus. Scriptural stories are "pictures of Christ" and early worship foreshadowed the worship of Jesus. God, with his foreknowledge, knew men would fail in obedience to him, but planned for our salvation by one final sacrifice for all and for all time! Here, it can be seen that just as my eyes were opened to scripture, so were the apostles:
Luke 24:31 "And their eyes were opened, and they knew him; and he vanished out of their sight.32 And they said one to another, Did not our heart burn within us, while he talked with us by the way, and while he opened to us the scriptures?"
Luke 24:44 " And he said unto them, These are the words which I spake unto you, while I was yet with you, that all things must be fulfilled, which were written in the law of Moses, and in the prophets, and in the psalms, concerning me. 45 Then (Jesus) opened he their understanding, that they might understand the scriptures,"
Today people are saved by reading about the promises and miracles of Jesus. Early Christians were saved by seeing Jesus in the OT:
Acts 18:28 "For he (Paul) mightily convinced the Jews, and that publicly, shewing by the scriptures that Jesus was Christ."
Romans 10:10 " For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation. 11 For the scripture saith, Whosoever believeth on him shall not be ashamed."
I'm comforted by the OT! It not only tells of the coming Messiah, but gives me words of wisdom and understanding. I have hope because OT prophecy tells about Jesus hundreds, even a few thousand years, before his virgin birth, how he was to be conceived, the mercy he was to provide, his death on the cross and his resurrection. My hope is multiplied by the evidence that god-inspired prophets were 100% accurate in telling of Christ! Early Christians were convinced by the OT that Jesus is the promised Messiah and they accepted Jesus as the promised Savior! Since the prophecy is 100% accurate, my faith is firm and my hope assured because I have faith and am saved by my belief and acceptance in the One promised! As we can see scripture tells of that hope:
Romans 15:4 "For whatsoever things were written aforetime were written for our learning, that we through patience and comfort of the scriptures might have hope."
Not only was the sacrifice of Jesus on the cross revealed to mankind hundreds of years before, but in the book of John scripture reiterates the detailed prophecy of how it would happen. Paul preaches to the disciples that Jesus death was foretold:
1 Corinthians 15:3 "For I delivered unto you first of all that which I also received, how that Christ died for our sins according to the scriptures;"
Do you read "scripture"? Do you read and understand the Old Testament! Some churches don't preach from the OT often and some not at all. Some focus entirely on the NT and any argument made from the OT is denigrated.
One thing we do know for sure: The OT is divinely inspired! It's God's word spoken and/or given to mankind. Being God's Word, the OT is holy and is right, fitting and honorable to be of great value if one seeks divine inspiration.
Start afresh right now! Read the OT and all the while ask "What's this got to do with Jesus?" However, read the NT first so you can answer that question as you read. Reiterating... the OT is all about Jesus!