A sacrament is an outward sign instituted by Christ to give grace. Only Christ instituted the sacraments, because only God can endow signs with the power to give grace. An outward sign is something perceived by the senses. The external thing or action is called the matter, and the formula of the words, the form, of the sacrament. (For example, we see the water used in baptism; we hear the words pronounced as the water is poured. These are sensible signs perceived by the senses of sight and hearing.) The sacraments signify the graces they actually give. Thus the washing in Baptism signifies the inward washing of the soul from sin. The sacraments always give the graces they signify, provided the recipient puts no obstacles [between himself and the grace of God]. It is principally through the sacraments that we obtain the grace of God. They are channels by which grace enters our souls, to feed and nourish them.
How many sacraments are there?
There are seven sacraments: Baptism, Confirmation, Holy Eucharist, Penance, Extreme Unction, Holy Orders and Matrimony. These are seven sacraments and only seven, no more, no less, for the simple reason that Our Lord instituted seven. These seven sacraments are a gift of love from the Son of God, a gift for which He paid His very life.
From whom do the sacraments receive their power to give grace?
The sacraments receive their power to give grace from God, through the merits of Jesus Christ. Each sacrament posses the power from God to make the soul of the recipient holy and pleasing to Him. This supernatural power is termed, Sanctifying Grace. (Sanctifying Grace is abiding and permanent and lost only by mortal sin. The sacrament that first gives this grace is Baptism. The sacrament that restores this grace to those who have lost it by sin is Penance. The other sacraments give an increase of Sanctifying Grace.) Each Sacrament also gives a grace proper to itself, a special effect on the soul, distinct from the effects of other sacraments; this is called Sacramental Grace. If received with the proper dispositions, the sacraments always give grace.
Reposted from http://www.sspxridgefield.com/sacraments
Baptism | Confirmation | Holy Eucharist | Penance | Extreme Unction | Holy Orders | Matrimony