Christ is our high priest. One of the functions of being a high priest is that Christ as a mediator. Christ is interceding between two parties. The first party is God the Father. God the Father cannot be approached unless there is a mediator between him and the party who wants to come to him. To approach God the Father outside of a mediator whom He has ordained results in the judgment of God. The only mediator that God has ordained is Christ Jesus, and the only party that Jesus mediates on behalf of is the church. The church is the object of the mediatorial work of Jesus.
When Jesus is mediating for the church he calls it into a participation of grace and glory. When Jesus applies the benefits of his work the recipient is only the church. Therefore when it is said that “there is no salvation outside of the church” (Calvin and Turretin) we should rejoice in this and not fight against this truth. Just as there was no salvation outside the ark when God’s judgment came on the earth during the flood, the church is a safe haven for her members protecting them from the judgment of God. Therefore, as Christians we should find our direction is the care of the church till “we arrive at the goal of faith” (Turretin 3.1.III)