One of the reasons for the change, according to the report, is that "scientific research generally supports the view that people who are attracted to someone of the same gender were born that way".
"This knowledge supports the view that same-gender sexual attraction can be understood as part of God’s good and diverse creation rather than unnatural," it says.
The Working Group on Doctrine report uses the expression "same-gender" instead of "same-sex" because it's easier to translate into various languages.
The report also notes the "the injustices which LGBTIQ people have suffered in society and in the church".
"It is common knowledge that discrimination against people because of their sexual orientation has very damaging impacts on their health and wellbeing."
"If the church is committed to learning from Jesus about challenging the injustice of excluding people then it will seriously consider extending marriage to couples of the same gender."
The proposal will now be considered by 265 members at the Uniting Church's 15th Assembly meeting in July – the church's national decision-making forum that meets once every three years.
President of Uniting Church in Australia Stuart McMillan told SBS News: "As you would expect, just as in the rest of the country, there is a wide range of views across the Uniting Church on marriage.
"We respect that people have a diversity of views that they come to from a range of different religious, cultural or personal perspectives.
"We also acknowledge that these discussions are painful for some people and we ask our members to show love towards each other and remain respectful throughout our conversations."
If the church decides to allow same-gender marriages, "authorised celebrants' freedom of conscience to celebrate or not to celebrate these marriages will be protected", he added.
The church has also released a summary of the report in other languages.