A central idea in The Quest of the Holy Grail is the power of possessing a magical object. The goblet that Joseph uses to catch the blood of Christ from the latter's wound becomes a miraculous item. Even before the crucifixion, the goblet itself was already significant in the story of Jesus Christ: it was the goblet that Christ drank from during the Last Supper. Interestingly, the wine that filled the goblet during the Last Supper symbolized the blood of Christ, and later on, it became the vessel of Christ's actual blood.

Later on in the story, Merlin, the famed wizard, tells King Arthur of the Holy Grail and the significance of the goblet. King Arthur, too, possesses a magical object: Excalibur, the sword in the stone that was fated to be in the possession of the future king. Both kings—Christ and Arthur—are associated with miraculous objects. The symbolism of the blood in the goblet also hints at a royal bloodline, or connects the royalty of Christ to the kingdom of King Arthur. In this sense, King Arthur is depicted as a successor to Jesus Christ.

Another similarity between the two kings is the fact that they each have a group of loyal men—as well as one traitor—who make up their inner circle. Christ had the disciples and was betrayed by Judas, while King Arthur has the Knights of the Round Table and is betrayed by Sir Lancelot. The quest for the Holy Grail can be seen as a quest for a divine power and the ability to preserve that power. In the beginning, the young Arthur finds himself divinely destined to rise above the circumstances in which he is born, just as Christ did.

That was Arthur's original "quest" for power. The connection between the story of Christ and that of King Arthur also shows the early dynamic between British royalty and Christianity. This relationship became especially prominent during the Crusades.