(CP) The Rev. Franklin Graham criticized contemporary Christian music star Amy Grant after she and her husband announced their plans to host a same-sex wedding for their niece at their farm, denouncing homosexuality as a sin.

In a Sunday Facebook post, Graham, the son of legendary evangelist Billy Graham and head of the Billy Graham Evangelistic Association, said, "God defines what is sin, not us; and His Word is clear that homosexuality is sin."

Graham took issue with Grant being quoted in a Washington Post article as saying: "Jesus, you just narrowed it down to two things: love God and love each other." The artist told the outlet about her and her husband's plans to host her niece's wedding at their farm. The wedding will be the family's "first bride and bride" nuptials, according to the report.

The 70-year-old Graham agreed that God calls Christians to love one another but cited John 14:15 to stress that loving the Lord means obeying Him.

"We have all sinned, and in order to have a relationship with God and spend eternity with Him in Heaven, we must turn from our sin and put our faith in His Son, Jesus Christ, who came to earth to die for our sins," Graham wrote.

Citing Acts 3:19, Graham contends that the Bible calls on people to repent their sins to God so that their sins "may be wiped out."

"For me, loving others also means caring about their souls and where they will spend eternity," he continued. "It means loving people enough to tell them the truth from the Word of God. The authority of God's Word is something we can never compromise on."

Grant became the first contemporary Christian music star to receive the Kennedy Center Honors earlier this month, a lifetime achievement award given to performance artists for contributing to the culture.

Upon learning that her niece declared her sexuality, Grant openly said her reaction was: "What a gift to our whole family to just widen the experience of our whole family."

"Honestly, from a faith perspective, I do always say, 'Jesus, you just narrowed it down to two things: love God and love each other,'" Grant said. "I mean, hey — that's pretty simple."

In 2013, Grant did her first interview for PrideSource.com, an LGBT news website, where she shared her views on faith and LGBT issues.

"I know that the religious community has not been very welcoming, but I just want to stress that the journey of faith brings us into community, but it's really about one relationship. The journey of faith is just being willing and open to have a relationship with God. And everybody is welcome. Everybody," Grant said.

The wife and Christian singer also told "Proud Radio" host Hunter Kelly last year about why it's important for her to set a "welcome table." Grant stated that she was invited to a "table where someone said, 'Don't be afraid, you're loved.' Gay. Straight. It does not matter."

"[It] doesn't matter how we behave. It doesn't matter how we're wired," Grant said, according to Church Leaders. "We're all our best selves when we believe to our core: 'I'm loved.' And then our creativity flourishes. We're like, 'I'm gonna arrange flowers on your table and my table.' When we're loved, we're brave enough to say yes to every good impulse that comes to us."

Graham, who also serves as the president of the Evangelical humanitarian aid agency Samaritan's Purse, frequently comments about current events on social media.

Graham recently responded on Facebook to a sermon by a University of Cambridge research student, who claimed that Jesus had a "trans body." The sermon, delivered on Nov. 20 by Joshua Heath, compared Jesus' side wound and blood flow to the groin in Jean Malouel's 1400 work Pietà to looking like a vagina.

The evangelist asserted that "to insinuate that Jesus Christ, the Holy Son of God, is transgender or to sexualize in any way His sacrificial death on the Cross for the sins of mankind is utter heresy."

Graham wrote that "the Bible warns us about false teachers," arguing that "this speaker and the dean at the University of Cambridge who defended him are false teachers, preaching heresy."

"[P]eople don't need messages from the pulpit that are trying to interpret art like this speaker was — people need the truth of the Word of God that has the power of God to change hearts and lives for eternity!" Graham stated.

© The Christian Post