The institution of marriage

Marriage is a divine institution.
So God created man in his own image, in the image of God created he him; male and female created he them. And God blessed them, and God said unto them, Be fruitful, and multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth. (Genesis 1:27-28)
And the LORD God caused a deep sleep to fall upon Adam, and he slept: and he took one of his ribs, and closed up the flesh instead thereof; And the rib, which the LORD God had taken from man, made he a woman, and brought her unto the man. And Adam said, This is now bone of my bones, and flesh of my flesh: she shall be called Woman, because she was taken out of Man. Therefore shall a man leave his father and his mother, and shall cleave unto his wife: and they shall be one flesh. And they were both naked, the man and his wife, and were not ashamed. (Genesis 2:21-25)
Male and female created he them; and blessed them, and called their name Adam, in the day when they were created. (Genesis 5:2)

Marriage is a social, legal, covenantal and specific institution.
Build ye houses, and dwell in them; and plant gardens, and eat the fruit of them; Take ye wives, and beget sons and daughters; and take wives for your sons, and give your daughters to husbands, that they may bear sons and daughters; that ye may be increased there, and not diminished. And seek the peace of the city whither I have caused you to be carried away captives, and pray unto the Lord for it: for in the peace thereof shall ye have peace. (Jeremiah 29:5-7)
For as in the days that were before the flood they were eating and drinking, marrying and giving in marriage, until the day that Noe entered into the ark, (Matthew 24:38)
Thou shalt not covet thy neighbour's house, thou shalt not covet thy neighbour's wife, nor his manservant, nor his maidservant, nor his ox, nor his ass, nor any thing that is thy neighbour's. (Exodus 20:17) 
Marriage and divorce were regulated under Moses' law. For examples, see above and Exodus 21:10, Leviticus 18:18, 20:14, and Deuteronomy 7:3, 25:5.
Yet ye say, Wherefore? Because the LORD hath been witness between thee and the wife of thy youth, against whom thou hast dealt treacherously: yet is she thy companion, and the wife of thy covenant. (Malachi 2:14)
Marriage is honourable in all, and the bed undefiled: but whoremongers and adulterers God will judge. (Hebrews 13:4)

Marriage is not an eternal institution.
And Jesus answering said unto them, The children of this world marry, and are given in marriage: But they which shall be accounted worthy to obtain that world, and the resurrection from the dead, neither marry, nor are given in marriage: (Luke 20:34-34)
[Except for the marriage of the Lamb and His bride -- Let us be glad and rejoice, and give honour to him: for the marriage of the Lamb is come, and his wife hath made herself ready. (Revelation 19:7)]