The sacraments are efficacious signs instituted by Christ through which the power of his saving grace comes to us. “Efficacious” means the sacraments bring about what they symbolize. Thus the symbolic washing in Baptism brings about a spiritual cleansing that removes all sin and elevates the Christian to share in “the divine nature” (2Pet 1:4).
Although the sacraments were entrusted to the Church and ministered through the Church, it is vital to recognize that the sacraments are primarily the work of Christ through the Holy Spirit. They are the ordinary means Jesus gave his Church through which men experience the dynamic transformation of his saving grace. The sacraments have power because they flow from the saving work of Jesus Christ.
Liturgy refers to the official public worship of the Church. Therefore, in one sense it refers to the whole complex of official worship services, rites, ceremonies, prayers and sacraments of the Church in contrast to private devotions. However, in a more restricted sense the word liturgy refers to the Church’s chief act of worship – the sacrifice of the Holy Eucharist, which is commonly called the Mass. In the Mass, Christ the head, makes present to us his unique sacrifice on the cross.