Support for same-sex marriage among members of The Church of Jesus Christ of Latter-day Saints (The Mormons) is gradually increasing.

According to a Public Religion Research Institute (PPRI) poll of 40,000 people released last week, support for marriage equality has increased 13 percent in the last three years to 40 percent among Mormons.

Pollsters, however, found higher support among Catholics, Muslims and Jews.

A majority (52%) of Mormons between the ages of 18-29 support legal marriage for gay and lesbian couples, a 43 percent increase since 2014, the poll found.

Support nationally is up 9 percent since 2013 to 61 percent of Americans.

(Related: Majorities in 44 states approve same-sex marriage, poll finds.)

In 2008, the Mormon church actively lobbied for passage of a California constitutional amendment that defined marriage as a heterosexual union. Seven years later, the church said that gay men and lesbians in a relationship are apostates.

Mormon Alex Landers told ABC News that she supports marriage equality because she has LGBT friends, including her best friend who is a bisexual man.

“I can't look at him and his boyfriend and tell them that they can't be happy and they can't love each other,” Landers, 20, told the outlet. “Heavenly Father loves us for who we are. He wants us to be happy, as long as we're treating people well and we're being who we truly are and we're not hurting anyone.”