Knoxville PrideFest is expected to draw around 10,000 people to World's Fair Park.
The Pride Parade started at noon on Saturday and included several churches.
In fact, half a dozen church congregations and 24 local clergy signed a statement in support of same-sex marriage.
The list was made public with Knoxville PrideFest 2013.
This is the first year PrideFest has included an Interfaith Worship Service.
It took place on Saturday morning at Tennessee Valley Unitarian Universalist Church in West Knoxville, with members from seven churches as well as Knoxville Jewish Alliance.
Rev. Laura Bogle spoke on behalf of Foothills Unitarian Universalist Fellowship.
"For so long being a person of faith has equaled anti-gay, discriminatory toward lesbian, gay, bisexual and transgender people, and you know that is just not the case," Rev. Bogle said.
Rev. Bogle and her partner, Katie Goslee, moved to Knoxville about a year ago with their daughter, Johanna.
"Actually we moved from California and so we weren't completely sure what to expect and we've found a lot of support and just a lot of friendly people, in places we didn't really expect," Goslee said.
This week, Exodus International announced it will close after 37 years. The ministry had claimed to offer a "cure" for homosexuality, but has now apologized to the LGBT community.
"The closing of Exodus International this week really impacted me. There's somebody that I reached out to as a teenager, desperate to not be gay, and alas... that is not something that I had control over," said Christopher Hamblin, worship coordinator for this year's Interfaith Worship Service.
Those at the service also discussed the US Supreme Court, which is expected to rule on two landmark gay marriage cases next week.
"That's what we came together to do today, to talk from different perspectives about why this matters, why are we talking about this so much, and what does it mean to us each," Hamblin said.
Hamblin said he expects the Interfaith Worship Service to be a yearly event during Knoxville PrideFest.