Jesus being the door seems odd, but we will see that it fits the shepherd metaphor, but it also enters into the larger symbolism of doors throughout Scripture. 

So firstly, the shepherd would have literally been the door to the sheep. He would have spent the night lying down in the opening of the pen in order to keep the sheep safely in and all of the things that could harm them out. The good shepherd protects the lives of his flock. 

Doors all throughout Scripture symbolize judgment. Inside of the door is safety, protection, and life. Outside of the door is danger, harm, and death. Think through some of the stories of judgment in Scripture. Adam and Eve after sinning are banished from Eden, the land of life, into the land of death outside of Eden. The gates of which are now protected by cherubim and a flaming sword. Noah’s ark same story different door. As the door of the ark shut those inside the ark escaped judgment and found life whereas those outside of the ark suffered judgment and destruction. In Sodom, the angel of the Lord literally shut the door to Lot’s house those inside were spared while those outside were stuck with blindness in judgment. The final plague in the Book of Exodus as the angel of death brought judgment on the land. Those who were saved were behind the doors that were painted with the blood of a sacrificial lamb while those who were judged were not.

Jesus is saying the only way to find safety, protection, and life is through Jesus. He is the literal door that we must go through to find abundant life. And the abundant life that he brings us we have neither earned nor deserve. It is a life that is bought by the precious blood of Jesus on the cross. A cross that makes us worthy to be his children only because he has chosen to make us his children. It is an abundant life that doesn’t end in death but continues on for eternity.