What is a Sacrament?

Answer

A sacrament is an outward sign of inward grace in that it bears its image and is its cause. It is a sacred and mysterious sign or ceremony, ordained by Christ, by which grace is conveyed to our souls. In every sacrament three things are necessary: the outward sign, the inward grace, Divine institution. Sacraments do not naturally signify grace; they do so because they have been chosen by God to signify mysterious effects. Against all innovators, the Council of Trent declared: "If anyone say that the sacraments of the New Law do not contain the grace which they signify, or that they do not confer grace on those who place no obstacle to the same, let him be anathema" (Sess. viii, can.vi). "If anyone say that grace is not conferred by the sacraments ex opere operato but that faith in God's promises is alone sufficient for obtaining grace, let him be anathema"
A sacrament is a spiritual covenant between God and man. We take upon ourselves the name of the Lord, to remember his blood which was shed for us and his body which was broken for us. We remember the atonement that he made for us. A sacrament is an outward sign of inward grace in that it bears its image and is its cause. In every sacrament three things are necessary: the outward sign, the inward grace, Divine institution. In biblical times, there were may sacraments held for all kinds of reasons, none pertained to that of the sacrament to our Lord but to other gods of the time. The Sacraments are seven in number: Baptism, Confirmation, Penance, Holy Eucharist, Holy Orders, Matrimony, Anointing of the Sick.
a formal religious act conferring a specific grace upon those who receive it.