The marriage covenant, by which a man and a woman establish between themselves a partnership of their whole life, and which of its own very nature is ordered to the well being of the spouses and to the procreation and upbringing of children, has between the baptized, been raised by Christ the Lord to the dignity of a sacrament. (CCL 1055) God himself is the author of marriage. Marriage is not a purely human institution despite the many variations it may have undergone through the centuries in different cultures, social structures, and spiritual attitudes. (CCC. 1603)
The essential properties of marriage are unity and indissolubility (CCL. 1056 & CCC 1614)
A marriage is brought into being by the lawfully manifested consent of persons who are legally capable. (CCL 1057)
So that the sacrament of marriage may be fruitfully received, spouses are earnestly recommended that they approach the sacraments of Penance and blessed Eucharist. (CCL 1065; CCC 1621)
Since God created...man and woman, their mutual love becomes an image of the absolute and unfailing love with which God loves man...This love which God blesses is meant to be fruitful. Scripture affirms that man and woman were created for one another. (CCC 1604 $ 1605)
The following are incapable of contracting marriage: 1) those lacking the use of reason; 2) those lacking discretionary judgment concerning essential matrimonial rights and obligations; 3) those who because of a psychological problem are unable to assume the duties of marriage. (CCL 1095)
In order for a marriage to be validly established, bride and groom must:
not have any impediments to marriage (e.g. being under the age of 16; in a pre-existing valid marriage; bound by religious vows/promises; being a close relation by blood or by adoption);
have the proper capacity to exchange consent;
consent to what the Church intends by marriage; and
exchange consent before a properly delegated priest or deacon and two witnesses. This is called the "form of marriage."