Q. 1. What does Baptism by Blood mean?
A. 1. Baptism by blood is the shedding of one's blood for the faith of Christ. He who has the intent of being baptised, but dies as a martyr while preaching the Gospel before receiving the Sacrament, he has received the Baptism by blood.
In the Catechism of the Catholic Church, we read,
"The Church has always held the firm conviction that those who suffer death for the sake of the faith without having received Baptism are baptized by their death for and with Christ. This Baptism of blood, like the desire for Baptism, brings about the fruits of Baptism without being a sacrament." [C.C.C. # 1258]