WHAT IS A SACRAMENT?
A sacrament is an outward sign of an invisible spiritual reality. Because humans are a unity of a physical body and a spiritual soul, God uses the means of physical objects and rituals to convey spiritual truths that we cannot detect using our senses.
This outward sign functions as a channel through which God imparts sanctifying grace into the soul. The sacraments are seven in number and have their source in the saving work of Jesus in his passion, death, and resurrection, and were established by Him for the sanctification of every member of His Church.