It's a symbol of the Atonement, the atonement that makes it possible for us to dare to stand before the throne of grace. Since the second century Christians have used the Pelican as a symbol of Christ's sacrifice for us. At one time it was believed that the pelican mother would feed her own blood to her young in times of famine.
The Atonement of Christ's blood, poured for me, by which I can say with full confidence, My Lord, and my God and without which I am only a worm.
He was despised and rejected by men;
a man of sorrows, and acquainted with grief;
and as one from whom men hide their faces
he was despised, and we esteemed him not.
Surely he has borne our griefs
and carried our sorrows;
yet we esteemed him stricken,
smitten by God, and afflicted.
But he was wounded for our transgressions;
he was crushed for our iniquities;
upon him was the chastisement that brought us peace,
and with his stripes we are healed.Isaiah 53: 3-5 ESV
So Jesus said to them,"Truly, truly, I say to you, unless you eat the flesh of the Son of Man and drink his blood, you have no life in you. Whoever feeds on my flesh and drinks my blood has eternal life, and I will raise him up on the last day. For my flesh is true food, and my blood is true drink.
John 6: 53-55 ESV
