Holy Baptism holds the first place among the sacraments, because it is the door of the spiritual life; for by it we are made members of
Christ and incorporated with the Church. (http://www.newadvent.org)
Reconciliation is a sacrament of the New Law instituted by Christ in which forgiveness of sins committed after baptism is granted through the priest's absolution to those who with true sorrow confess their sins and promise to satisfy for the same.
The Holy Eucharist
The Holy Eucharist refers to Christ's body and blood present in the consecrated
host on the altar. Eucharist refers to one of three aspects of Christ's body and
blood -- as sacrifice during the Consecration of the Mass, as Holy Communion,
and as Blessed Sacrament. These three aspects form the core of Catholic belief
on the Holy Eucharist.
Sacred ministers, those who serve the spiritual needs of others, in the Catholic Church are ordained by a bishop and by means of a special sacrament called Holy Orders. This sacrament can only be received once, just like Baptism and Confirmation, but a man may also be ordained to a higher order up to the third degree. Jesus Christ instituted the Sacrament of Holy Orders at the Last Supper simultaneously with his institution of the Sacrament of Holy Eucharist. In order to be able to change bread and wine into the body and blood, soul and divinity of Christ, you need priests who have been given this power by virtue of their ordination.
Anointing of the Sick
This sacrament was called Extreme Unction (last anointing), not because it was the last sacrament you received before passing on from this life but because it was the last anointing a person received. Baptism and Confirmation were the first two times a person would've been anointed. It was commonly called Last Rights, because before antibiotics and penicillin, more people died than recovered from disease and injury. When the sick and injured weren't expected to survive, Extreme Unction was the sign that no more could be done, so the sick and injured were spiritually preparing for death. That's why even today, many of the elderly get upset when the Catholic hospital chaplain brings his purple stole and oils. They presume the worst and only see the sacrament as the begriming of the end. In reality, the Anointing of the Sick is to offer prayers for possible recovery, but the more important intention is to give strength to the soul of the sick person. The Church believes that the sacrament offers a special grace to calm the spirit. The Sacrament of Anointing of the Sick also remits (absolves) all sins the person is sorry for but did not previously confess in the Sacrament of Penance. The Anointing of the Sick involves using Oil of the Sick - olive oil blessed by the bishop during Holy Week. Anointing with oil is not a magical or good-luck gesture but a sincere sign of supernatural assistance to coincide with the physical medicine and treatment already been given.