Apart from salvation being by grace alone, in Christ alone, through faith alone as seen in the scriptures alone, and for the glory of God alone, another thing Martin Luther emphasized was the priesthood for believers. Man no longer needs an intermediary between him and God.
We are now priests, 1 Peter 2:9. Priesthood means we have the responsibility to show God to our world. This is our greatest privilege. This is what it means to be IMAGO DEI.
Although Jesus died as one, He rose as many that He should bring many sons to glory. He did this by baptism, Colossians 2:12. Baptism is a supernatural operation by which we become beneficiaries of the work of Christ. If we are this close to God, then we don’t need an intermediary.
As priests, we have the privilege and responsibility to show God to the world, Acts 1:8, 2 Corinthians 5:17-20.