Not all speeches backed gay marriage, however.
The public gallery burst into an impromptu rendition of We Are Australian immediately after the bill passed.
The House of Representatives is widely expected to pass the legislation on Thursday, after the bill drew broad cross-party support.
More than 100 MPs had delivered speeches, many emotional, in the lead-up to the final vote with most in support of changes to the Marriage Act.
All amendments were struck down, and the bill passed unchanged from the one that cleared the Senate last week.
Many same-sex marriage supporters have travelled to Canberra to witness the outcome in the lower house.
Media captionWill you marry me?
Turnbull told Parliament that while nothing in the bill threatened religious freedoms, he wanted more reassurances for the millions of Australians who oppose marriage equality.
The bill is expected to reach a final vote later on Thursday, after parliament considers a series of amendments from conservative government MPs and the Greens.
"We must not fail to recognize that there is honest, heartfelt anxiety about the bill's impact on religious freedom", Turnbull said.
"We have made sure that we have removed any element of discrimination in this bill while ensuring that religious freedoms are protected", he added.
The only potential obstacle to the law passing on Thursday would be if marriage equality opponents managed to amend the legislation.
"Australians are sick of excuses and they're sick of delays", Entsch said.
Gay marriage was endorsed by 62 per cent of Australian voters who responded to a government-commissioned postal ballot by last month.