All love that depends on a transient thing, when the thing has ceased, the love ceases (too); but the love that depends not on a transient thing never ceases. What is that love which depends on a transient thing? The love of Amnon and Tamar. And that which depends not on a transient thing? The love of David and Jonathan.
Source: Pirke Aboth, chapter 5.
The love that Amnon had for Tamar, being lustful and solely based on her looks, was bound to last only a short time (2 Sam 18). In contrast, David loved Jonathan not for any sexual reasons (despite some modern claims to the contrary) but because of a friendship that loved the person and not the accidents that fade away – looks, prestige, wealth, etc. “Jonathan’s life became bound up with David’s life; he loved him as his very self” (1 Sam 18:1, NABRE). Yet many today believe that, without a sexual partner, life cannot be totally fulfilling. For example, Bertrand Russell in chapter 6 of Marriage and Morals wrote:
I believe myself that romantic love is the source of the most intense delights that life has to offer. In the relation of a man and woman who love each other with passion and imagination and tenderness, there is something of inestimable value, to be ignorant of which is a great misfortune to any human being.
In this modern attitude can be seen a reason for the push in different Christian churches for allowing same-sex marriage. Proponents often argue that it is an injustice to deprive gay Christians of a romantic partner. However, this is not the traditional Christian view. St. Augustine, St. Gregory of Nyssa, St. Jerome, along with many other Fathers, not to mention St. Paul and Christ himself, thought that celibacy was a holier state than married life. The loss of asceticism and of clerical celibacy in the West has likely played a role in changing this view.
There are, however, voices to the contrary. Online, there are not a few Catholics with a high view of tradition, many of whom attempt to remind others of “the exaltedness of celibacy.” Happily, among the Orthodox, Archimandrite J. P. Manoussakis expressed a similar opinion: “Making marriage a norm to which everyone is expected to conform is for me problematic. The abolition of clerical celibacy in the aftermath of the Reformation was perhaps a ﬁrst step toward this direction that is now completed by granting marital status upon homosexual couples.” (Note that he is opposed to same-sex marriage; certain extreme Orthodox sites badly distort and misinterpret his words here – perhaps because his words were being translated from a Finnish website).
Prominent currents in Western culture excessively emphasize sexuality, to the point where watching pornography and premarital sex are assumed to be normal behavior, in contrast to earlier eras when even masturbation was taken to compromise virginity. In their desire to be faithful, many devout Christians reduce this emphasis but still fail to question it outright in light of Christian morals. But the Apostle tells us the kingdom of God is not food and drink but righteousness and peace and joy in the Holy Spirit (Rom 14:17). It must be acknowledged, then, that the object or basis of love cannot be transient but must bind the lives of its lovers together forever, like David and Jonathan, or St. Augustine, who wrote of his mother’s death in these terms: “Because I had lost the great comfort of her, my soul was wounded and my very life torn asunder, for it had been one life, made of hers and mine together” (Confessions, 9.12).