As a Jew I find that the entire OT leads up to the coming of Jesus, Who is the Messiah.
Adam and Eve sinned, which brought depravity to mankind. God promised to send the Messiah to restore fellowship back to man with God. Meanwhile, God established a covenant with Abraham to establish His people as Abraham trusted God.
Later, God established a covenant with His people through Moses. Primarily, He established the "sin offering" where a lamb was slain for the sins of each individual.
Finally, the Messiah came (the lamb of God who takes away the sins of the world). His death was the ultimate death for our sins. He then defeated death by His resurrection.
Now, all that needs to happen is for each individual person to accept Jesus as his Savior and accept Him as Lord of his life. Then, he can have fellowship with God.