Some quotes from the CCC:
1266–The Most Holy Trinity gives the baptized sancifying grace, the grace of justification: enabling them to believe in God, to hope in him, and to love him through the theological virtues; giving them the power to live and act under the prompting of the Holy Spirit through the gifts of the Holy Spirit; allowing them to grow in goodness through the moral virtues. Thus the whole organism of the Christian’s supernatural life has its roots in Baptism.
1285–Baptism, the Eucharist, and the sacrament of Confirmation together constitute the “sacraments of Christian initiation,” whose unity must be safeguarded. It must be explained to the faithful that the reception of the sacrament of Confirmation is necessary for the completion of baptismal grace. For “by the sacrament of Confirmation, [the baptized] are more perfetly bound to the Church and are enriched with a special strength of the Holy Spirit. Hence they are, as true witnesses of Christ, more strictly obliged to spread and defend the faith by word and deed.”
1299–In the Roman Rite the bishop extends his hands over the whole group of the confirmands. Since the time of the apostles this gesture has signified the gift of the Spirit.
1303–From this fact, Confirmation brings an increase and deepening of baptismal grace: …] it increases the gifts of the Holy Spirit in us;
The St. Pius V Catechism states, “As nature intends that all her children should grow up and attain full maturity …], so the Catholic Church, the common mother of all, earnestly wishes that, in those whom she has regenerated by Baptism, the perfection of Christian manhood be completed.”