Why Do We Celebrate the Sacrament of Confirmation?
Confirmation perfects Baptismal grace; it is the sacrament which gives the Holy Spirit in order to root us more deeply in the divine filiation, incorporate us more firmly into Christ, strengthen our bond with the Church, associate us more closely with her mission, and help us bear witness to the Christian faith in words accompanied by deeds. (CCC 1316)
In the Sacrament of Confirmation, we renew our baptismal promises and commit to living a life of maturity in the Christian faith. As we read in the Lumen Gentium (the Dogmatic Constitution of the Church) from the Second Vatican Council:
Bound more intimately to the Church by the sacrament of confirmation, [the baptized] are endowed by the Holy Spirit with special strength; hence they are more strictly obliged to spread and defend the faith both by word and by deed as true witnesses of Christ. (no. 11)
Scriptural Foundation for Confirmation
In the Acts of the Apostles, we read of the coming of the Holy Spirit on Pentecost. After receiving the power of the Holy Spirit at Pentecost, the Apostles went out and confirmed others, showing Confirmation to be an individual and separate sacrament: Peter and John at Samaria (Acts 8:5-6, 14-17) and Paul at Ephesus (Acts 19:5-6). Also, the Holy Spirit came down on Jews and Gentiles alike in Caesarea, prior to their baptisms. Recognizing this as a confirmation by the Holy Spirit, Peter commanded that they be baptized (cf. Acts 10:47).
Confirmation is a Sacrament of Initiation whereby the graces of Baptism are brought to completion and the recipients receive the graces of the Sacrament and a greater outpouring of the Holy Spirit. Baptism, Confirmation and Holy Communion make up the three sacraments of initiation into the Roman Catholic Church and must all be completed to be a fully initiated member of the Church.