Peter declares in 1 Peter 2:9 that one of the identities of the follower of Christ is as a priest. In the Old Testament the priestly role was a unique position between the holy and the common. Priests represented God's will to the community and represented the community before God. Because of the Fall (sin), fallen image-bearers could not relate directly to God. They needed the priests to intercede on their behalf. This was the privilege and the responsibility of being a priest. The highest privilege and responsibility was left to the High Priest to enter the Holy of Holies on behalf of the people. This was the inner sanctuary that was marked off by a heavy duty curtain. Not just anyone was allowed in. It was where God's holiness dwelled. Once a year the High Priest could go in on behalf of the people but it required the High Priest to go through a lot of preparation so that they could be pure enough to meet with God. God's presence was not a place where just anyone could go.
But with Jesus, everything changed. Jesus came so that we did not need other people to be the go-between between us and God. When Jesus died a dramatic thing happened. The curtain the separated the common from the holy was torn in two (Matthew 27:51). No longer did humanity need other human beings to intercede on their behalf before God. The writer of Hebrews makes note of the new relationship that exists now when he writes,
Therefore, brothers and sisters, since we have confidence to enter the Most Holy Place by the blood of Jesus, by a new and living way opened through the curtain, that is, his body, and since we have a great priest over the house of God, let us draw near to God with a sincere heart in full assurance of faith, having our hearts sprinkled to cleanse us from a guilty conscience and having our bodies washed with pure water. (Hebrews 10:19-22)
As followers of Christ we have an access to God that was previously unavailable. We are as priests who bridged the gap between the common and the divine. In fact as people who have been granted access to God, we become God’s representatives, his renewed image-bearers, to the world around us. Because of the work of Christ on the cross, we have the ability to commune with God personally and without barrier. Part of who we are is as priests.