The Bible calls marriage an eternal union between a man and a woman, in which they attain spiritual and bodily unity and become one whole. The institution of marriage appears at the conclusion of the creation of the world; marriage becomes an integral feature of human life. Moreover, the biblical account can be understood to mean that the very concept of "the human being" should first be applied to the couple made up of a man and a woman. According to the witness of Gen. 2:18-24, a person needs a "helper"; that is, in isolation he cannot fulfill the task set before him to "cultivate and keep" God's creation. For this, the complete unity ("one flesh") of two different beings proves necessary. In the words of the sacred author, this unity surpasses every earthly bond, even bonds of blood. The indication that two take part in this union also affirms, in the biblical context, the ideal of monogamy.

The presence of the Lord Jesus Christ at the wedding in Cana of Galilee is traditionally regarded as an important witness to God's blessing of marriage, as is the fact that Christ more than once compares the Kingdom of Heaven to a wedding feast.

Established by God in the Garden of Eden before the fall, marriage belongs to God's original design for the world, a design not yet damaged by sin. Among other things, an important function of marriage is the multiplication of the human race. The marriage union is realized in love, and this also bears witness to the original character of the institution of marriage. The Bible repeatedly uses marriage as an image of the love that unites people. Inspired lines of the psalms, the prophets, and the writings of the wise are devoted to the greatness and beauty of this unity in love; the Song of Songs is devoted to it in a special way. Marriage is sanctified by the Creator's will for human unity, and therefore it is not only emotional and physical unity, but first of all spiritual and religious unity. For this reason the Bible often uses marriage as a symbol of the covenant with God and, more broadly, as a symbol of religion in general (see Hos. 2:1-10).

The high ideal of marriage that characterizes Holy Scripture did not become the norm of people's actual life at once. At the beginning of biblical history, the people of Israel held ideas and customs characteristic of all Near Eastern peoples and cultures of that era. This applies first of all to the permissibility of polygamy and divorce. Many persons mentioned in the Bible had marriages involving two or even more spouses, and references to divorce are also frequent. It is characteristic that the Old Testament speaks neither of polyandry nor of divorce initiated by women. Together with the different requirements of marital fidelity imposed on men and women, this reflects the inequality of the sexes accepted in the ancient East. Only gradually, and very slowly, were these views of the ancient Jews outgrown.

The Sinai legislation, at the end of the second millennium BC, directly requires monogamous marriage only of the high priest; this norm is not yet applied to the other Israelites. By the era of the Second Temple, at the end of the sixth century BC, monogamous marriage becomes the norm among the chosen people. Already at that time polygamy becomes a rare exception, and later it disappears altogether. In the New Testament, only monogamous marriage is called undefiled.

In the middle of the fifth century BC, the prophet Malachi proclaims that divorce, permitted by the Sinai legislation, is displeasing to God. To leave one's wife means, according to the prophet's word, to wrong her; at the same time the prophet Malachi calls divorce treachery on the man's part. Both are inadmissible according to the spirit of the Law. In the Russian Synodal translation of Mal. 2:16, following the Greek text of the Septuagint, the wording is "if you hate her, send her away, says the Lord." Another translation, more consistent with the context, reads, "I hate divorce, says the Lord." The latter translation is based on the Hebrew original and entered a number of ancient and modern translations in this form. In any case, Malachi's statement as a whole unambiguously condemns divorce.

The Lord Jesus Christ definitively forbids divorce in the New Testament. He explains the permission for divorce, given by Moses in the Sinai legislation, by the hard-heartedness of the Israelites of that era, in other words, by their inability to rise above their own ideas to the norm of biblical monogamous and indissoluble marriage.

The writings of Israel's wise, above all the Song of Songs, as well as Ecclesiastes, the Proverbs of Solomon, and the Wisdom of Jesus son of Sirach, speak of the love of a man and a woman in marriage as the most beautiful thing that can exist in human earthly life. Ecclesiastes, who regards everything as vanity and finds joy in nothing, in essence makes an exception only for marriage. He speaks of marriage almost as the only bright spot in the darkness of vain life. Sirach also values marriage highly, paying more attention to how the intrusion of evil into married life poisons life.

In addition, the Sinai legislation regulates some questions that belong not so much to Revelation as to marriage law. Thus, it forbids marriage within certain close degrees of kinship and provides some protection for a woman's rights against male arbitrariness. In addition, the Law forbids marriages with women of other peoples in order to avoid the temptation of paganism. The history of Israel gives many confirmations of how serious the danger of falling away from the faith became for those who were married to pagan women. This position, so important in the era of the chosen people's spiritual formation, later led to consequences that were far from simple. Thus, after the return from captivity, Ezra and Nehemiah, renewing the covenant, demanded that the Israelites send away their foreign wives. The prophet Malachi's words about treachery toward wives may be an echo of these events. This position undergoes a radical change in the New Testament. Thus, the apostle Paul in the First Epistle to the Corinthians, while repeating the prohibition of divorce, says that the faith of one spouse can, through love, serve for the salvation of the other, unbelieving spouse.

In the marriage law of the Old Testament, among other things, the concept of levirate is defined: in a levirate marriage, the younger brother, or another relative, of an Israelite who has died childless is obliged to marry his widow. The first child born in such a marriage was considered the descendant of the deceased man, not of his "physical" father. Levirate marriage was conditioned, on the one hand, by the need to continue priestly, Levitical lines, and also by property reasons.

The epistles of the apostles, comparing relationships in marriage with the relationship of Christ and the Church, require spiritual unity from spouses and speak of the leading role of the man, who bears responsibility before God for the whole family. In addition, the New Testament repeatedly mentions the need for marital fidelity.