The Sacraments of Initiation are those events in which one comes to be one of Christ's Faithful, according to the Catechism of the Catholic Church.

There are three Sacraments of Initiation: Baptism

Baptism

In Christianity, baptism is for the majority the rite of admission , almost invariably with the use of water, into the Christian Church generally and also membership of a particular church tradition...

, Confirmation, and the Eucharist

Eucharist

The Eucharist , also called Holy Communion, the Sacrament of the Altar, the Blessed Sacrament, the Lord's Supper, and other names, is a Christian sacrament or ordinance...

. The reception of these mysteries

Sacred Mysteries

The term sacred mysteries generally denotes the area of supernatural phenomena associated with a divinity or a religious ideology.-Pre-Christian religious mysteries:...

 is required for one to be considered a full member of the Catholic Church.

Children are normally baptized as infants. Adults are normally baptized after enrollment as a catechumen

Catechumen

In ecclesiology, a catechumen , “‘down’” + ἠχή , “‘sound’”) is one receiving instruction from a catechist in the principles of the Christian religion with a view to baptism...

, either formally, as in the Latin Rite, or more informally, as in some Eastern Catholic Churches. Though not a true member of the Church, catechumens may have some share in Christ

Christ

Christ is the English term for the Greek meaning "the anointed one". It is a translation of the Hebrew , usually transliterated into English as Messiah or Mashiach...

, according to the Church.

According to the Catechism, Baptism makes one a member of Christ's Body and prepares one for the reception of the other sacraments. Confirmation is the anointing

Anointing

To anoint is to pour or smear with perfumed oil, milk, water, melted butter or other substances, a process employed ritually by many religions. People and things are anointed to symbolize the introduction of a sacramental or divine influence, a holy emanation, spirit, power or God...

 in the Holy Spirit

Holy Spirit

Holy Spirit is a term introduced in English translations of the Hebrew Bible, but understood differently in the main Abrahamic religions.While the general concept of a "Spirit" that permeates the cosmos has been used in various religions Holy Spirit is a term introduced in English translations of...

. The Eucharist gives one the "food of eternal life", and allows one to receive and conform to Jesus Christ.