From the Baltimore Catechism:
670. What is Confirmation? Confirmation is a Sacrament through which we receive the Holy Ghost to make us strong and perfect Christians and soldiers of Jesus Christ.
671. When was Confirmation instituted? The exact time at which Confirmation was instituted is not known. But as this Sacrament was administered by the Apostles and numbered with the other Sacraments instituted by Our Lord, it is certain that He instituted this Sacrament also and instructed His Apostles in its use, at some time before His ascension into heaven.
672. Why is Confirmation so called?
Confirmation is so called from its chief effect, which is to strengthen or render us more firm in whatever belongs to our faith and religious duties.
673. Why are we called soldiers of Jesus Christ?
We are called soldiers of Jesus Christ to indicate how we must resist the attacks of our spiritual enemies and secure our victory over them by following and obeying Our Lord.
What is meant by anointing the forehead with chrism in the form of a cross?
By anointing the forehead with chrism in the form of a cross is meant that the Christian who is confirmed must openly profess and practice his faith, never be ashamed of it; and rather die than deny it.
693. Why should we know the chief mysteries of faith and the duties of a Christian before receiving Confirmation?
We should know the Chief Mysteries of Faith and the duties of a Christian before receiving Confirmation because as one cannot be a good soldier without knowing the rules of the army to which he belongs and understanding the commands of his leader, so one cannot be a good Christian without knowing the laws of the Church and understanding the commands of Christ.
694. Is it a sin to neglect Confirmation?
It is a sin to neglect Confirmation, especially in these evil days when faith and morals are exposed to so many and such violent temptations.
695. What do we mean by “these evil days”?
By “these evil days” we mean the present age or century in which we are living, surrounded on all sides by unbelief, false doctrines, bad books, bad example and temptation in every form.
697. Are sponsors necessary in Confirmation?
Sponsors are necessary in Confirmation, and they must be of the same good character as those required at Baptism, for they take upon themselves the same duties and responsibilities. They also contract a spiritual relationship, which, however, unlike that in Baptism, is not an impediment to marriage.
698. Which are the effects of Confirmation?
The effects of Confirmation are an increase of sanctifying grace, the strengthening of our faith, and the gifts of the Holy Ghost.