A: St. John has been honored as a martyr from the earliest days after his death, because of an incident related by Tertullian, in which John, while in Rome, was placed in a pot of boiling oil but emerged unharmed.
At first, the term martyr applied only to the Apostles. Once Christians started to undergo persecution, the term came to be applied to those who suffered hardships for their faith. Finally, it was restricted to those who had been killed for their faith. The early Christian period before Constantine I was the “classic” age of martyrdom. A martyr’s death was considered a “baptism in blood,” cleansing one of sin, similar to the effect of baptism in water. The “baptism in blood” provides an even greater picture, showing the faith that the martyr has for his/her Savior.
St. John of the Cross wrote that we will be judged by our love. Catholic teaching is that we must have attained perfection before we will enter heaven. Perfection is complete love of God and neighbor. Baptism in blood demonstrates this devotion.
The un-baptized who suffer martyrdom thereby become justified and attain heaven (Matt. 10:32, 39).
Early Christians venerated martyrs as powerful intercessors, and their utterances were treasured as inspired especially by the Holy Spirit.
A system of degrees of martyrdom that was developed in early Christianity. Some of these degrees bestow the title of martyr on those who sacrifice large elements of their lives alongside those who sacrifice life itself. These degrees were mentioned by Pope Gregory I in Homilia in Evangelia, he wrote of “three modes of martyrdom, designated by the colors, red, blue (or green), and white.”
A believer was bestowed the title of red martyr due to either torture or violent death by religious persecution.
The term “white martyrdom” was used by the Church, “for those such as desert hermits who aspired to the condition of martyrdom through strict asceticism.”
Blue (or green) martyrdom “involves the denial of desires, as through fasting and penitent labors without necessarily implying a journey or complete withdrawal from life”. Also along these lines are the terms “wet martyr” (a person who has shed blood or been executed for the faith) and “dry martyr” which is a person who “had suffered every indignity and cruelty” but not shed blood, nor suffered execution.