How do we know that Christ is central to God's plan of salvation?

From the foundation of the world, Christ's sacrificial role was established to ensure the salvation of His people. Various passages throughout Scripture convey this truth, asserting that God's sovereign design encompassed the necessity for a Redeemer from before creation itself. This understanding affirms that every believer has assurance in their salvation based on the unchangeable plan of God, fulfilled in Christ. The Bible reveals that it is in Christ that we find the fullness of God’s plan, aligning both the Old Testament types and New Testament fulfillment.