With due respect to friend Andrew, I will have to register some mild dissent to his comment to the previous post. While I believe that children are the blessing of a marriage, a childless marriage may also be a blessing. Solovyev in The Meaning of Love devotes some pages to this issue, saying that "Ordinarily the significance of sex love is supposed to lie in the increase of the race, to which it serves as a means. I consider this view unsound..." It is unsound because individuality possesses an independent spiritual significance in mankind, the individual being the absolute form (image) of rational consciousness. But, he continues, (I paraphrase) Each individual can become a living reflection of the absolute whole, a conscious and independent organ of the universal life. But to do this it must be in the truth. Normal man - "original and immediate" - is not in the truth. "So long as the living force of egoism in man does not encounter another living force opposed to it, knowledge of the truth is only an external illumination... The truth, as a living force, taking possession of the inward essence of the man, and effectively rescuing him from false self-assertion, is termed love. Love, the abrogator of egotism, is the justification and salvation of individuality. Which is to say that in man, individuality and egotism are not absolutely coincident, or fated to coincide - this indeed being the drama of life and love. ..
"...The meaning of human love, speaking generally, is the justification and deliverance of individuality through the sacrifice of egotism."
It is a mistake, says Soloyvev, to treat love as a merely natural process: "Such significance as speech possesses for the organization of human society and culture, love also possesses in a still greater degree, for the creation of true human individuality...As the true significance of speech consists not in the process of uttering in itself,...so the true significance of love consists not in the simple experience of this feeling, but in what is accomplished by means of it, in the work of love...
...the separation between the male and female elements of the human creature is already a state of disintegration and the beginning of death. Only the human being in his entirety can be immortal. But what does the true union of the sexes consist of? Ordinary sexual relations may be described as a kind of "carrion-worship," for a part (i.e. the body) is put in place of the whole. Purely physiological union does not deliver from death. Man as a social animal finds it natural to restrict the physiological function with claims of the social and moral law, which curbs and conceals the animal function and allows for the maintenance of the family. But this remedy does not really address man's divided state. "Only by actions which are the result of conscious faith do we enter into real correspondence with the realm of the truly-existent, and through it into real correlation with our 'other.' ... This is the spiritually regenerative part of the sex relation - or rather its spiritual essence, of which its material aspect is but the symbol or type. The mystery of regeneration is bound up with the mystery of the universe and the spiritualization of matter. ..
This is a very brief summary of certain portions of Soloyvev's treatise on love, a treatise almost unknown in the West. To be sure the practice of contraception was the first technological wedge separating marriage from its procreative aspect. But this technological wedge was in itself the result of decades, even centuries, of materialistic thinking. But traces of the moral understanding of male-female bond lingered much longer in literature - indeed Jane Austen's Pride and Prejudice is a nearly perfect expression of it. The heroine has to find her way not to love but to the truth in love - and the hero, for his part, is likewise chastened by his encounter with the force of the truth in love. Both hero and heroine unleash a kind of maelstrom of moral development whose final fruit is the symbolic unity of marriage - a pinnacle earned, not merely gained.
There is something of the raw exchange of electric energy in true male-female encounter, the proving-ground of human moral life. I think it would be better to think of marriage in terms of these "electric energies," the exchange and interchange of positive and negative, than in the begetting of children. For this exchange and interchange are moral forces, and it seems to me apparent today that humanity is gravely lacking in the capacity to undergo this kind of moral training. Nor do I believe that modern humanity should complacently assume that it will always have the power to procreate.  The materialism and coarsening of human relations are proceeding apace, and at some point - perhaps in the none too distant future - the spiritual world will call a halt to unconscious procreation and demand from humanity a grateful participation, a spiritualized understanding, a will to affirm the continuance of human life, and a humble opening to the grace that comes from above.
 A whole essay needs to be written on the abdication of modern womanhood from the tasks of moral guardianship. Modern men are as a result lost and society is profoundly unbalanced. The cancerous growth of the State, which now openly practices torture, violates international standards with impunity, and so forth, are the result of the profound loss of moral energy in society brought on by the levelling of the two sexes into some kind of "uni-mass." The Sexual Revolution serves one entity, and one entity only: the Mammonist State.
 And I mean something quite different here from the resort to technology as a means to propagate. This is but a further symptom of disintegrative materialism. Besides, human beings do not "propagate" and only an animalization of man can proceed under this false notion. Human beings "procreate" - that is, open themselves to the emergence of new human life in partnership with the Divine. "As husband I have gained Jehovah," said Eve on the birth of Cain - or in more standard translation, "I have gotten a man from the Lord." (Gen 4:1) The procreative and the "thinking" function (i.e. the opening to the channel of grace by means of intellectual subtilization and moral practice) are in essence one.