Our God, who is Love, humbled Himself and became man. For our sake, He was crucified, died, and rose again, defeating death and giving us the hope of eternal life with Him. In His love for us, Jesus Christ instituted the sacraments as efficacious signs of God's grace, meaning that these outward signs really bring about the invisible reality of that which they signify.
For example, baptism really brings about the cleansing of our souls and our newness as an adopted son or daughter of God; Reconciliation really brings about the forgiveness of our sins; and the Eucharist really is the Body, Blood, Soul, and Divinity of Jesus Christ.
Guided by the Holy Spirit, the Church recognizes that there are 7 sacraments instituted by Christ: Baptism, Reconciliation, Confirmation, Eucharist, Matrimony, Holy Orders, and Anointing of the Sick.