A motion calling on the Executive to introduce same-sex marriage legislation was rejected by the Assembly, on 1 October 2012.
The Green Party's Steven Agnew said it was an opportunity to send a message to same-sex couples that "we see their love as equal".
He said it was not the case that churches would be forced into performing same-sex weddings.
The North Down MLA noted that the Prime Minister, David Cameron was "now coming out in favour of same-sex marriage".
Michelle McIlveen of the DUP said it was "simply a myth that this is an equality issue".
"Everyone is free to marry," she said.
Bronwyn McGahan of Sinn Fein quoted the the 1916 Declaration and its avowal to "cherish all the children of the nation equally".
"We cannot pretend to be for equality and the add the word 'but'", she added.
Roy Beggs of the UUP was concerned about the implications of the motion for churches.
He said "civil and religious liberties across the UK could be affected by this decision".
Mr Beggs said his party regarded the motion as a matter of conscience, and members would have the right to vote as they saw fit.
Colum Eastwood of the SDLP spoke in favour of the motion, describing it as "an affirmation" of the value of marriage.
Anna Lo said the Alliance Party was in favour of the motion with the proviso that "robust protections" were put in place for faith groups.
Ulster Unionist Basil McCrea said he would probably be one of the few on the unionist benches to speak in favour of the motion.
He said there were members of the house who were unable to speak in favour of the motion "despite the position members of their family find themselves in", and members "carried away on urgent constituency business".
Jim Allister of the TUV said "this is not a matter equality, this is a matter of the perversion of marriage".
Replying to the debate, Finance Minister Sammy Wilson said there was no "no widespread demand" for the changes asked for in the motion.
"I am opposed to gay marriage," he said.
The minister said he represented "the general view that is held in this society".
The motion was defeated on a cross-community vote.
The vote was held after Question Time. You can see the vote