Before He ascended into heaven Our Blessed Lord decided to establish means of communicating to the souls of men the graces He had merited by His life and death. For this purpose Our Savior willed to use external ceremonies, signs which could be perceived by men through their bodily senses. Humanbeings derive their knowledge by the use of their senses, and what appeals to their senses makes a greater impression than something that is perceived by the intellect alone; hence, Our Lord decided to suit His means of grace to man's nature. Accordingly, He instituted seven signs, or external ceremonies, capable of giving grace. He chose the particular signs to satisfy the most urgent spiritual needs of men. And, as will become more apparent in the lessons to follow, He adapted the sacraments to a plan of the spiritual life very similar to the course of man's natural life from the cradle to the grave.
A sacrament is an instrument of God's power and goodness. Just as an artist, using his brush as an instrument, paints a beautiful picture, so God through the sacraments draws His own image on the soul of man. However, the sacraments give grace dependently on man's cooperation. It is true, when a child who has not reached the age of reason receives a sacrament, God gives him the graces of the sacrament without demanding any dispositions. But when a person has once reached the use of reason, he must do his part in order to be sanctified. Such a person cannot receive a sacrament validly _ that is, really _ unless he has at least a general intention of receiving it. The external rite could indeed be forced on him, but it would not be a real sacrament unless he consented to receive it. Moreover, one who has attained the age of reason cannot receive a sacrament fruitfully _ that is, with its graces _ unless he has in his soul suitable dispositions as a becoming preparation. Generally speaking, the disposition required of an adult for the reception of a sacrament of the dead _ that is Baptism or Penance _ is sorrow for sin based on faith; and the essential disposition for a worthy reception of one of the sacraments of the living is the possession of the state of sanctifying grace.
However, it is generally believed that if a person in mortal sin receives a sacrament of the living, unaware of his unworthiness and with imperfect contrition for his mortal sins, he will receive the state of grace. This is certain in regard to Extreme Unction, for St. James says, of the sick person who receives this sacrament, "If he be in sins, they shall be forgiven him" (James 5:15).
Most of the sacraments can be administered only by a priest or a bishop. However, two of them _ Baptism and Matrimony can be administered by laymen, as we shall see in the lessons on these sacraments. The Holy Eucharist can be consecrated by no one except a priest; but after it is consecrated, one who is not a priest can administer it. Ordinarily the Church allows only priests and (under certain conditions) deacons to give Holy Communion, but in extraordinary circumstances even a layperson would be permitted to administer the Blessed Sacrament. Thus, any Catholic could consume the Holy Eucharist or give it to another Catholic, if this were necessary to prevent it from being profaned; and if no priest could be had, and the Blessed Sacrament were available, a layman would be allowed to administer Holy Communion as Viaticum to one in danger of death.
Sometimes a priest administers a sacrament conditionallythat is, with the intention of conferring it only on condition that certain circumstances of which he is uncertain, are present. Thus, if a priest, baptizing a baby, is not certain whether or not the child has been previously baptized, he administers the sacrament with the condition: "If you are not baptized." If a priest, called to a person who has been seriously injured, is not sure whether or not the person is still living, he gives Extreme Unction with the condition: "If you are alive."
Our Lord Himself instituted the seven sacraments for our sanctification, but the Church has instituted various rites and ceremonies for the administration of the sacraments, to manifest more clearly their significance and to impress us more deeply with their holiness.