I don't know why it is that we miss the continuity of the Old and New Testaments; we tend to apply different attribute to Gods, neglect God's people pre-Christ, and pretend as if God's plan has been altered due to worldly circumstances. But one crucial truth remains; it has always been God's plan to rescue sinners by the blood of Jesus. Even from within the pain of the Fall, we see a promise (Gen. 3:15), and then shortly a plan to bless the world, to grow a great big church through one man Abraham (Gen. 12). The book of Galatians, and Romans, and Hebrews, and everywhere else, shows that we are part of Abraham's family, not a new family because Plan A didn't work out. The seed of Isaac would bring the Messiah Jesus, and at his coming the Gentiles are included into that people, now the family we call the church.
Further, now that all barriers have been broken down, just as we saw in the curtain being removed, we have God the Spirit amongst us in the church, just as God dwelt with his people in the tabernacle, then the temple. But we have full access to him as now, at the great pinnacle of the story, the Son of God paid the price for us and was raised from the dead, promising that we will follow after him in glory. Our sin (the great seperator between God and man) has been eliminated as a chasm; we're accepted, all God's people, because of the righteousness of Christ and his once-for-all offering of himself as a sacrifice for us. In some ways, this isn't new: God has always desired to be amongst his people, he's allows made a way for sacrifices as atonement, which meant God could dwell there - but now we have a greater sacrifice (Hebrews), and one that can permanently pay for sins.
We see the remembrance of Passover in the Old, God's passing over of sinners in destruction by the blood of the Lamb, and the Lord's Supper in the New, the meal where re remember God's passing over us in judgment because of the blood of the Lamb, Jesus. We have circumcision in the Old, God's covenant sign with his people in the Old, baptism in the New: and prayer, worship of him, meditating on God's law, looking forward to the redeemer in the Old, looking back on him in the New.
You fit somewhere in this story, in fact, all people do, believers or unbelievers, whether those who will inherit life eternal, or those who will face judgment, still bearing the guilt of their sin. We celebrate this great mission of God, and his grace to us that while we are still sinners, Christ died for us (Romans 5:8). He knew you would sin, he knew you would be lost, and he put you in his sights anyway, that you would be brought into his family. And that is a tale we could tell again and again before we drift off to sleep, and it would never get old.