At Confirmation we receive the gift of the Holy Spirit, and Christ confirms the baptism that we have already received. Greater awareness of the grace of the Holy Spirit is conferred through the anointing of chrism oil and the laying on of hands by a bishop or a priest.
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 celebration of the Sacrament of Confirmation we renew our baptismal promises and commit to living a life of maturity in the Christian faith. Lumen Gentium (the Dogmatic Constitution of the Church) from the Second Vatican Council states:
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)