In October, Barack Obama, in response to a recent spike in suicides among America's gay teenagers, launched a video speaking out against homosexual bullying. In the same month, Shmuley Boteach, the "Hollywood Rabbi", wrote an article for the Wall Street Journal criticising the harsh view taken of gays in most Orthodox congregations in the USA. Both events beg the same question: how do we square the biblical prohibition against homosexuality with modern notions of equality?

In the early 1990s, some years before multiple retroviral drugs significantly increased survival rates for people infected with HIV, I worked on fundraising at the AIDS Unit at the Royal Free Hospital, which meant that I worked closely with the gay community that made up the majority of the population being treated at the centre. It was sometimes harrowing - such as the time that I sat and watched one of the patients heavily involved in fundraising activities slowly fade, but also often uplifting, particularly as I observed the commitment of the medical staff.

It was, to say the least, an unusual setting for an Orthodox boy from a traditional north-west London family. In the Orthodox schools, synagogues and in the Jewish community generally that I came from, homosexuality was very much taboo. It was something that we knew existed out there in the gentile world, but was unmentionable within the boundaries of our Jewish lives.

In 2010, in mainstream British society, things are very different. Gay rights, openly gay politicians and the growing influence of public policy in promoting equality for gays (such as the recent Equality Act) have made homosexuality an accepted part of modern life. Except when it comes to faith.

In the Orthodox world, nothing has changed and why, indeed, should it? Just as in normative Christianity and Islam, Jewish law very clearly regards homosexuality as a grave sin and there is no more scope within the boundaries of halachah for changing this than for abolishing the Sabbath. While many would rightly argue, as does Rabbi Boteach, that it is the "sin" rather than the "sinner" that should be condemned, Orthodox Judaism fundamentally disapproves of the very idea of a gay lifestyle, seeing it as an abrogation of core Jewish values centred on the family, the roles of men and women, and the first commandment of the Torah to engage in procreation. The Orthodox tradition is to bless a newborn child that they should go on to "Torah, chupah and good deeds". It could never be exchanged for "Torah, chupah or civil partnership".

What we cannot do is to deny that a conflict exists

Of course, this collision of ideas leaves modern Orthodoxy with a significant problem. We might all agree that we should follow President Obama's lead in opposing gay bullying. Yet the secular idea of diversity proclaims that everyone is equal in their humanity, equally deserving of respect and dignity in all aspects of their lives. Therein lies the rub for Orthodoxy - for surely condemning homosexuality as unnatural and undesirable inevitably opens up the door for direct and even violent discrimination.

Could, say, a teacher who taught his class in the morning that homosexuality is banned by God realistically be able to discipline a child in the afternoon for engaging in homosexual name-calling in the playground during the lunch break?

There are no easy answers. The strength of democratic societies is that opposing views can and do coexist. Those of us, such as myself, who adhere to the tenets of Orthodox Judaism should be free, along with those with similar views in the other Abrahamic faiths, to discuss and promote the core ideas of their faith, of which opposition to homosexuality as a lifestyle choice is clearly one. Indeed, recent trends in public policy to misuse anti-discrimination legislation to prevent free speech on matters of belief in relation to sexuality are very worrying, and the gay community has in some cases done itself no favours by supporting such misuse. What we cannot do, in the UK as much as in the States, is deny that a conflict exists.

The growing demands for the gay community to be treated equally in all areas of life cannot be easily reconciled with Orthodox Jewish attitudes to homosexuality. Perhaps the only answer lies in remembering, as I believe Judaism calls on us to do, that we are all created in "the image of God". Is this Jewish idea not, after all, the basis of democratic society - recognising that however strong our disagreements may be, we are all still joined by our common humanity.

So when I sat and watched the sad decline of patients at the Royal Free all those years ago - they weren't HIV/AIDS cases, or gay people, or straight people. They were just people, deserving, whether in sickness or health, of the compassion and understanding of their fellow man.

Joseph Mintz lectures on education at South Bank University