A lot of Christians have no qualms about following God’s instructions in the Bible, such as helping the poor and keeping the Sabbath holy. However, there are three areas of sanctity that many of them avoid even talking about.

Pastor Rick Warren of Saddleback Church wrote on his website that these “controversial issues” are the things that Christians need the most courage to speak up about. “Why? Because not only will many people disagree with you about these topics, they will also be very passionate in their argument,” he said. “It takes an uncommon courage to stand up against that kind of pressure.”

The first issue is about the sanctity of life. Warren said God has a purpose for every unborn child, adding that every Christian must speak for those who can’t speak for themselves yet. He said some 70 million Americans would most probably be alive now if they had not been aborted.

Next, Warren said Christians should be brave about upholding the sanctity of sex. The pastor stressed that sex is only for marriage. Since it was God’s idea, it isn’t dirty or wrong—rather, it is very holy. “God’s instructions never change: Premarital sex is unacceptable to God. Living together without being married is unacceptable to God. Adultery is unacceptable to God. Pornography and the objectification of women are unacceptable to God,” he said.

Lastly, Warren discussed the sanctity of marriage, which should solely be between one man and one woman for life. It’s true that polygamy was reported during the time of the Bible, but Warren said the Bible does not approve everything it reports.

“There are many issues of life where people of goodwill can disagree. For example, there’s no economic recovery plan in the Bible, and Christians can disagree on that,” he said.

“But if you call yourself a disciple of Christ, you need to line yourself up with what God says about the sanctity of these three things. And you need to have the courage to stand up for them, even and especially when it’s not the popular or politically correct thing to do,” Warren said.

The Saddleback Church pastor also tackled the truth and authenticity of the Bible. Although some people might question the veracity of the Bible’s content, he said there’s a world of “objective” evidence out there.

Some historians argue that Solomon could not have owned the horses the Bible said he owned back then, because it was said that no one owned horses yet at the time. “But then thousands of horse stables were found in an archaeological dig,” the pastor said.

At the same time, the Bible is filled with eyewitness accounts. Moses was present when God parted the Red Sea. Joshua was there to watch Jericho fall. Jesus’ disciples all saw Him resurrect from the dead after being nailed to the cross.

“The internal evidence of the Bible also includes the fact that it tells one story with consistency — though it was written over 1,500 years on three different continents by 40 different authors from every walk of life. No human being could account for that. It’s an amazing example of God’s abilities,” Warren said.

Read more at What are the 3 things most Christians feel uncomfortable talking about?