Answer:
The practice of confirmation has its roots in the early church, when it was thought to be a safeguard against oppression for recently baptized Christians.
What does it mean in the Catholic religion to be “confirmed”?
In early Christian history, once things got a little organized, someone interested in joining the Church would be baptized, then anointed with chrism, then admitted to the Eucharist all in one liturgy, during the vigil of Easter. The minister of this combined Christian Initiation was the bishop, assisted by deacons (male and female).
In the Catholic Church, this is still mostly the case for adults converting to Christianity.
By about the 8th century, Christianity had spread so that there were so many people in a bishop’s territory, that he could not do all the baptisms himself at the cathedral. So, this part of initiation was delegated to local parish pastors, but these baptisms would still have to be ‘confirmed’ by the bishop. This was done by reserving the second step of the initiation, the anointing with chrism, to the bishop.
This evolved, in the Latin tradition, to a separate sacrament, so that by the time of the Council of Trent in the 16th century, baptism and confirmation were completely separated. By the early 20th century, even the correct order of these three sacraments of initiation was abandoned. Efforts to return to the ancient practice grew out of the 20th century liturgical movement and gained new impetus at Vatican II, but are still in process.
So, for most, being confirmed is an adolescent or adult choice of embracing your full membership in the Church, a sign of maturity and commitment of faith, and a readiness to exercise leadership and ministry in some fashion as a full and active member of the community.