Baptism is a Sacrament which cleanses us from original sin, makes us Christians, children of God, and heirs of heaven. Baptism is necessary to salvation, because without it we cannot enter into the kingdom of heaven. The priest is the ordinary minister of Baptism; but in case of necessity any one who has the use of reason may baptize. Whoever baptizes should pour water on the head of the person to be baptized, and say, while pouring the water: I baptize thee in the name of the Father, and of the Son, and of the Holy Ghost.
There are three kinds of Baptism: Baptism of water, of desire, and of blood.
Baptism of water is that which is given by pouring water on the head of the person to be baptized, and saying at the same time: I baptize thee in the name of the Father, and of the Son, and of the Holy Ghost.
Baptism of desire is an ardent wish to receive Baptism, and to do all that God has ordained for our salvation.
Baptism of blood is the shedding of one´s blood for the faith of Christ, such as in the cases of martyrdom. Baptism of desire or of blood is sufficient to produce the effects of the Baptism of water, if it is impossible to receive the Baptism of water.
Biblical references: Acts 2:38-39; Acts 22:16; 1 Peter 3:21; John 3:5; Matt 19:14;
Luke 18:15-16; Col 2:11-12; Rom 6:13; Acts 16:15; Acts 16:33; 1 Cor 1:16; Mark 16:16;
Rom 5:18-19; Mark 10:14; Jos 24:15; Matt 8:5ff; Matt 15:21ff