When Christians attend gay weddings of friends and family members, it implies that they are giving their "moral approval" to the union, according to Rev. Albert Mohler, president of the Southern Baptist Theological Seminary.

In his new book "We Cannot Be Silent," Mohler said people should strengthen their resolve and boycott these weddings.

The book, which will be released on Oct. 27, shares Mohler's strong views against gay marriages, according to Charisma News. He admitted that boycotting the wedding of loved ones can be extremely difficult, but it is important to provide tough love during these occasions.

"At some point, attendance will involve congratulating the couple for their union," he wrote. "If you can't congratulate the couple, how can you attend?"

Mohler is not one to shy away from controversial topics. In the past, he voiced his views against delaying marriage and limiting family size. He also said the Roman Catholic Church teaches a "false gospel" and that the pope holds an "unbiblical office."

He also has serious concerns against yoga, saying that Christians who do that exercise "either deny the reality of what yoga represents or fail to see the contradictions between their Christian commitments and their embrace" of it.

With his new book, Mohler is once again stirring up some criticisms, especially from those who oppose his views. One such person is director Chris Hartman of the Louisville-based non-profit organisation Fairness Campaign, which fights discrimination against those who have different sexual orientations and gender identity.

"Dr. Mohler's self-righteous intractability on this issue — even banning followers from simply attending the weddings of their LGBT loved ones — can cause nothing but strife, heartache and hardship," he said.