Among the effects of baptism is the initial reception of the Holy Spirit by the newly baptized. This first reception opens us to even greater gifts from God toward His dwelling fully within each of us, strengthening us with His abiding presence. It is by way of the sacrament of confirmation that such abiding of God in the Holy Spirit is fully offered to us.
In the Code of Canon Law, canon 879 defines the sacrament of confirmation as that which “strengthens the baptized and obliges them more firmly to be witnesses of Christ by word and deed to spread and defend the faith.” This definition indicates an increase in the life of the baptized, both in relation to the grace of God dwelling within them and in their living out the call to witness to Christ by their lives. Canon 879 goes on to express that such an increase in the life of the baptized is the completion of the graces received in baptism by which the faithful are more perfectly bound to the Church through the Holy Spirit.
In considering the origins of this sacrament, the Sacred Scriptures are filled with occasions of individuals receiving the “anointing” of the Holy Spirit. In particular, on Pentecost when the Holy Spirit descended upon the Apostles in the form of tongues of fire, they received the Holy Spirit and accordingly began their mission to proclaim Christ to the whole world. Throughout Acts of the Apostles many individuals as well as large groups are said to receive the gift of the Holy Spirit upon accepting faith in Christ – some of whom are said to receive it at a separate time from their baptism through the laying on of hands by an apostle (see Acts 8:14-17). It is this laying of hands that the Catechism points out as one of the foundations for confirmation. Additionally, the anointing with the “chrism” (the holy oil with balsam scent) likewise is rooted in the practice of the ancient Church as the outward sign or way in which confirmation is conferred.
While the Church acknowledges that a clear history of confirmation is not easily discerned, it is evident from the earliest centuries that the completing of baptism through confirmation was typically administered through the bishop. In fact, while priests can (and do) sometimes administer the sacrament, the reality of the bishop being the minister is understood as having led to our long-time (and current) practice of confirmation being given separate from baptism – as bishops cannot practically be present at every baptism. As time went on, the realities of the bishop laying his hands (or single hand) upon the one being confirmed and his anointing them with the chrism to “seal” them with the gift of the Holy Spirit were understood as the visible signs that confer the grace of receiving the Holy Spirit.
In more recent times, the sacrament of confirmation has remained one of varied customs. For example, among members of the Church today are those who were confirmed in elementary school, others confirmed in middle school, with still others confirmed in their high school years (as has occurred in the Diocese of Duluth over several decades). While the essential element of being anointed with chrism is consistent, even the manner or the laying of the hand has seen adjustment – as some among the elderly likely can recall the bishop striking them on the face after anointing them, which was symbolically meant as a reminder of readiness to suffer anything for the sake of the faith in Christ. These variations, however, in no way change the fundamental purpose of confirmation as completing baptism with the fullness of the gift of the Holy Spirit, enabling the recipient to more perfectly live the faith.
For further reading: In the Catechism of the Catholic Church, the paragraphs 1285-1292 and 1315-1316 give an overview of the what the sacrament of confirmation is, along with brief reference to its historical development.