It is evident from its celebration that the effect of the sacrament of Confirmation is the full outpouring of the Holy Spirit as once granted to the apostles on the day of Pentecost. From this fact, Confirmation brings an increase and deepening of baptismal grace:

• it roots us more deeply in the divine filiation which makes us cry, "Abba! Father!";
• it unites us more firmly to Christ; 
• it increases the gifts of the Holy Spirit in us; 
• it renders our bond with the Church more perfect;
  it gives us a special strength of the Holy Spirit to spread and defend the faith by word and action as true witnesses of Christ, to confess the name of Christ boldly, and never to be ashamed of the Cross.

CCC 1302-1303