The MOST Theological Collection: A Basic Catholic Catechism
"Part XI: The Seven Sacraments in General"
Jesus came that we might have life, and have it abundantly (John 10:10). The life He speaks of is that of grace; sanctifying grace makes us "sharers in the divine nature" (2 Peter 1:4). That is it gives us the basic ability to take part in the infinite knowledge and love that flow within the Holy Trinity. We call that life supernatural, since it is above and beyond the natural possibilities of any creature.
He won this life for us by His sacrificial death; He imparts it to us chiefly through the Sacraments.
Sacramentum in pagan Latin meant an oath of allegiance to the military commander; Christians soon referred this to Christ, but also broadened the word to mean anything religious and mysterious. But it was good for precision to speak more exactly. So eventually, by the 12th century, an agreement arose to use Sacrament to mean a sacred sign or rite established by Christ to give grace. In this light, it is an inexact use of the word to call the Church a Sacrament. Rather, the Church is the institution where we find these Sacraments and the fulfillment of all our spiritual needs.
For this reason, "God wills all to be saved, and to come to the knowledge of the truth" (1 Timothy 2:4). The second half of the line shows He wants all to have the special favor of full membership in the Church. Yet, as we saw in our treatment of the necessity of the Church in Part Five, He has also made provision for those who achieve something less than full membership, if they fulfill certain minimum conditions.
The power of the Sacraments is such that they confer grace by the very fact that they are rightly conferred, if only the recipient does not put up an obstacle.
Only baptized persons can receive the other Sacraments. To receive validly - so that it counts - an adult needs to have the intention to receive: God does not go against our free will which He has given. For valid and also profitable reception of Baptism, Penance, and the Anointing, there are also required faith, hope, and at last imperfect sorrow for sin. (In the case of infants, the intention is supplied by the Church). The state of grace is not needed for Baptism and Penance, but is needed for the other Sacraments, though the Last Anointing, in emergency, can make up for even that lack.
The Sacraments give sanctifying grace, which means, the basic ability of the soul to take part in the vision of God in the next life. If one already has this grace, they can increase the souls' capacity, for that vision is infinite. They also give sacramental grace, that is, the special help to carry out the obligations imposed by each Sacrament. This includes a special claim to such helps in the future, when needed. We should remember that, and call on that claim with confidence.
Baptism, Confirmation, and Holy Orders in addition produce the sacramental character, a permanent, indelible spiritual sign conforming them to Christ in the various ways signified by those Sacraments. Since this character is indelible, these three Sacraments cannot be repeated, though there are as it were degrees of Holy Orders.