THE DOOR

In the Bible, human beings are compared to sheep ... for we are prone to wander. When we surrender our lives to Jesus Christ we come under His care ...  

For you were like sheep going astray, but have now returned to the Shepherd and Overseer of your souls. (1 Peter 2:25)

He takes full responsibility for our needs, our safety, and our guidance ...

The Lord is my Shepherd; I shall not want. He maketh me to lie down in green pastures: He leadeth me beside the still waters. He restoreth my soul: He leadeth me in the paths of righteousness for His name's sake. Yea, though I walk through the valley of the shadow of death, I will fear no evil: for Thou art with me; Thy rod and Thy staff they comfort me. (Psalm 23:1-4)

Not only is Jesus seen as our Shepherd, but also as the 'Door' through which we enter into a saving relationship with the Father ... 

Then Jesus said to them again, “Most assuredly, I say to you, I am the door of the sheep. All who ever came before Me are thieves and robbers, but the sheep did not hear them. I am the door. If anyone enters by Me, he will be saved and will go in and out and find pasture." (John 10:7-9)

Notice that He proclaimed ... I am THE door (not merely 'a' door). 

There is one entryway into God's Kingdom ... Jesus said, I am the Way and the Truth and the Life. No one comes to the Father except through Me. (John 14:6)

If you receive Christ as Lord you become part of 'His sheepfold'. You have entered through 'The Door' which leads to eternal life.