By Saint Bede the Venerable
As forerunner of our Lord’s birth, preaching and death, the blessed John showed in his struggle a goodness worthy of the sight of heaven. In the words of Scripture: "Though in the sight of men he suffered torments, his hope is full of immortality." We justly commemorate the day of his birth with a joyful celebration, a day which he himself made festive for us through his suffering and which he adorned with the crimson splendor of his own blood. We do rightly revere his memory with joyful hearts, for he stamped with the seal of martyrdom the testimony which he delivered on behalf of our Lord.
There is no doubt that blessed John suffered imprisonment and chains as a witness to our Redeemer, whose forerunner he was, and gave his life for him. His persecutor had demanded not that he should deny Christ, but only that he should keep silent about the truth. Nevertheless, he died for Christ. Does Christ not say: I am the truth? Therefore, because John shed his blood for the truth, he surely died for Christ.
Through his birth, preaching and baptizing, he bore witness to the coming birth, preaching and baptism of Christ, and by his own suffering he showed that Christ also would suffer.
Such was the quality and strength of the man who accepted the end of this present life by shedding his blood after the long imprisonment. He preached the freedom of heavenly peace, yet was thrown into irons by ungodly men; he was locked away in the darkness of prison, though he came bearing witness to the Light of life and deserved to be called a bright and shining lamp by that Light itself, which is Christ. John was baptized in his own blood, though he had been privileged to baptize the Redeemer of the world, to hear the voice of the Father above him, and to see the grace of the Holy Spirit descending upon him. But to endure temporal agonies for the sake of the truth was not a heavy burden for such men as John; rather it was easily borne and even desirable, for he knew eternal joy would be his reward.
Since death was ever near at hand through the inescapable necessity of nature, such men considered it a blessing to embrace it and thus gain the reward of eternal life by acknowledging Christ’s name. Hence the apostle Paul rightly says: You have been granted the privilege not only to believe in Christ but also to suffer for his sake. He tells us why it is Christ’s gift that his chosen ones should suffer for him: "The sufferings of this present time are not worthy to be compared with the glory that is to be revealed in us."
From Homily 23: CCL 122, 354, 356-357