God created sex. Priests created marriage.

Voltaire

There is no observation more frequently made by such as employ themselves in surveying the conduct of mankind, than that marriage, though the dictate of nature, and the institution of Providence, is yet very often the cause of misery, and that those who enter into that state can seldom forbear to express their repentance, and their envy of those whom either chance or caution hath withheld from it.

Samuel Johnson

Keep your eyes wide open before marriage, half shut afterwards.

Benjamin Franklin

Love is moral even without legal marriage, but marriage is immoral without love.

Ellen Key

More belongs to marriage than four legs in a bed.

Rainer Maria Rilke

If there is such a thing as a good marriage, it is because it resembles friendship rather than love.

Michel de Montaigne

Where there's marriage without love, there will be love without marriage.

Benjamin Franklin