Okay, for several days I've been getting 503 Server Errors when I attempt to access active threads, so my apologies if anything I say duplicates points already made.
First and foremost, in my view Jesus meant exactly what He said when he identified the commandments to love God with one's whole self and one's neighbor as ourselves, and the Golden Rule, as encapsulating all the Law and Prophets. Indeed, in the Parable of the Sheep and the Goats he equates the two: anything done to another is done as to Him.
By the "Sabbath was made for man" teaching, we see the proper application of these two commandments: they are the principles by which the other commandments are to be applied. "Thou shalt not kill" does not mean "Never ever kill anyone for any reason whatsoever"; rather, it means "Do not take the life of another into your own hands, to do murder unto him." If a just war calls for the killing of your country's enemy, or defense of self of those depending on you calls for killing the person menacing your/their lives, then you are complying with the commandment as applied through those principles.
"Judge not, lest you be judged" is not a prohibition but a monition, a warning of a severe moral choice. It ranks with "I have put before you today life and death, a blessing and a curse; therefore, choose life." It means avoid judging if at all possible, and if you judge, judge in like manner as you yourself would wish to be judged -- because that is indeed the measure by which you will be judged if you do so. Judge with brotherly love, compassion, forgiveness, a true understanding of the circumstances of another, just as you would wish to be judged. The first dozen verses of Philippians 2 give us our touchstone -- emulate Jesus, who was humble and, though worthy of all things, thought Himself not above others but humbled Himself even to death on a cross. The Parable of the Unforgiving Servant underscores the fate in store for those who fail to extend mercy even as they have been extended it.
It is also instructive to look at Peter's encounter with Cornelius. Under the Law it was a sin for a Jew to take a meal with Gentiles, making him or her unclean. The Holy Spirit gives Peter the famous vision of the sheet coming down from Heaven filled with foods clean and unclean. Many understand this to mean the abolition of the dietary Law, the abolition of clean and unclean food. But Peter himself says it's more than that: "God has shown me that I should not call any man common or unclean." It's not a freedom from dietary Law; it's a freedom from judging others as less righteous than ourselves.
Now, how does this apply to homosexuality? Well, first, let us note that the so-called "clobber passages" (Lev. 18:22, Rom. 1:26-27, I Cor. 6:9, and the rest) do in fact condemn real and execrable sins. For many of us, reading them in the context of the passages in which they are found and of the culture of the authors and hearers/readers leads us to believe that they are not, as first impressions might suggest, a blanket condemnation of same-sex sex, but rather condemnations of sinful acts committed through same-sex sexual acts. Compare the seduction of a teenage girl with the joyful sexual union of husband and wife, to get a good parallel -- it is not the acts themselves, malum in se, but the sinful reason for them, that is the sin condemned.
However, even if this essay into Biblical moral analysis is in error, the basic principle of the Great Commandments and the Golden Rule still holds. Even if same-sex sexual acts were always sinful, the proper behavior for a Christian is not to judge and condemn his fellow man, but to encourage right behavior and repentance comassionately and with understanding of the other.
The so-called "homosexual lifestyle" as it seems to be envisioned by those condemning it is one of hedonistic promiscuous sex, a complete rejection of Christian values. In this regard, it is much like "the singles scene" for heterosexuals, where one picks up a different one-night stand at a bar each night. But what is the heterosexual to repent of, here? He is not called on to be celibate, necessarily, but to eschew promiscuity and casual sex with another seen totally as sex object, instead substituting for it the idea of loving sex only within the bounds of a lifelong exclusive commitment -- marriage, in fact.
This is, I believe, the standard to which a homosexual Christian should hold himself or herself. Eschew promiscuity and hedonism; restrict one's sex to marriage. And in this regard, what God views as marriage is the commitment made between the two members of the couple, the 'ministers of the sacrament' in Catholic parlance. Not whether the state or some third party's church recognizes that marriage as valid, but whether the couple themselves mean the vows the made to each other and keep them, is the core of what a marriage truly is.
This is the pont at which the common comparison to paedophilia, inappropriate behavior with animals, etc., falls flat on its face. A child or adolescent is likely to be misled by the adult and in any case cannot by his/her very nature as child or adolescent make a mature lifelong commitment. A beast cannot make a commitment as an equal. While a child, a teen, a dog, a cat, can and does love, that love is not the committed erotic love of a mature adult entering into marriage. This is why such comparisons are blatant insults to the gay person.
It is possible that I may be wrong in thinking any of this. But I will stake my self on the idea that I am in fact following Christ's commandments, the ones He Himself said were most important and the summary of all the others, in pursuing this view. "Hier ich stehe; ich kannst nein ander."