“The Happy Prince” is a story with a clear Christian ethos that can be read as an allegory of the sacrifice and compassion of Christ. In the Bible, Jesus’s crucifixion—through which he sacrifices himself out of his compassion for mankind—is held up as the ultimate ideal of virtue.
Similarly, in “The Happy Prince” both the Swallow and the Prince make sacrifices for the good of others. The Prince asks the Swallow to pluck out his jeweled eyes and strip his golden coating in order to help the poor. These acts demonstrate the Prince’s compassion while also mirroring the stripping of Jesus, whose garments were torn for him before his crucifixion.
What's more, the Swallow makes a great personal sacrifice by staying with the Prince to help him carry out his acts of charity, with his decision to do so ultimately costing him his life. Indeed, the story makes clear that the Swallow knows this is the cost of his actions, as he repeatedly mentions the growing coldness of the city. The Swallow’s love for the Prince, however, proves greater than his personal self-interest, demonstrating a certain selflessness that some might see as aligning with Christian values.
The virtue of the Swallow and Prince’s sacrifices is confirmed by the story’s ending:
“Bring me the two most precious things in the city,” said God to one of His Angels; and the Angel brought Him the leaden heart and the dead bird. “You have rightly chosen,” said God, “for in my garden of Paradise this little bird shall sing for evermore, and in my city of gold the Happy Prince shall praise me.”
Here, God himself asserts the virtue of the Swallow and the Prince, thus cementing the connection between the Swallow and the Prince's story and the biblical story of Christ's sacrifice on the cross.