Hebrews 2:17 Wherefore in all things it behoved him to be made like unto his brethren, that he might be a merciful and faithful high priest in things pertaining to God, to make reconciliation for the sins of the people.
Reconciliation is the process by which there is restoration of a friendly relationship. This takes into account the relationship was once harmed. The word reconciliation above is a form of the Greek word used in Romans 3:25 for propitiation. The root our reconciliation is the propitiation that was the sacrifice of Christ. The fruit of the propitiation is our reconciliation. We can have no reconciliation with God until the enmity that was our sin was dealt with in Christ’s propitiation. Reconciliation is between God and man where propitiation was between God the Father and God the Son.
Ephesians 2:16 And that he might reconcile both unto God in one body by the cross, having slain the enmity thereby:
Christ made propitiation for the sins of the people. God would require sufficient payment for sins and what more can be paid than the life and blood of the Son of God. This blood not only propitiated the wrath of God but it restored the relationship between God and man. By His propitiation, we are right with a holy God. God no longer carries enmity within Himself toward our sin. He has been propitious to us by the death of His Son. God could require no more than the death of His Son to restore us to Himself. When Christ cried it is finished all that God would require to right the wrong that we had done by our sin was completed. He would require nothing in addition and at that time we were reconciled.