February brings Valentine’s Day, and the Christian writer whose advice 21 years ago left lots of valentines unsent has revised his thinking.

Joshua Harris—author, former senior pastor of Covenant Life Church, and the firstborn of Christian homeschooling pioneers Gregg and Sono Harris—is still most famous for something he did at age 21: He wrote a best-selling book, I Kissed Dating Goodbye. Twenty-one years later, Harris is revisiting the subject by working on a documentary project called I Survived I Kissed Dating Goodbye, which will follow Harris as he and his readers reflect on the impact of his book.

I asked Harris why he’s making the film, how he feels and thinks about his book now, and whether he’d recommend his own book to his teenage children. Here are edited excerpts of our conversation.

You were 21 when you wrote IKDG. I used to think the idea of courtship was ridiculous. I was a teenager and wanted to make out with girls. Then when I broke up a two-year relationship in high school, I felt convicted, I felt regret, I felt I had mistreated this girl.

My parents and other homeschooling parents were already talking about the problems of modern dating, and I listened to them for the first time. After meeting Joel Belz, I became inspired to publish my own magazine for young Christians, where I wrote an article on dating and courtship. The response was huge, so I wrote a book that caught on like wildfire.

Why? One, legitimate problems in modern dating. Christians trying to uphold Biblical sexual ethics felt frustrated with the lack of specific guidelines. Two, parents from the sexual revolution wanted something different for their kids. Three, the book came out during the late 1990s, when people were still concerned about AIDS. Plus, my book had a catchy title.

Looking back, how do you view the 21-year-old Josh Harris who wrote IKDG? He was a very young man asking questions and wanting to honor God. I wanted to call my generation to higher standards. I was frustrated because everyone (including me) in my youth group was pushing physical boundaries in relationships. I thought: We need to pursue purity and honor God in every part of our life.

‘People latch on to movements for simple answers and promises. Even now as I revisit this issue, I don’t want to fall into the trap of thinking this is the real answer. We need to go to God humbly as a community and recognize there’s no one-size-fits-all approach.’

Looking back now, I came up with simple solutions when life is very complex. I thought I saw all these things so clearly, that if people just lived a certain way, it would lead to certain results, but that’s not what the Bible teaches. Truth is, you can walk with Jesus and have your heart broken. You can save yourself for marriage and have a terrible marriage.

What do you think the young Josh Harris missed? He was simplistic in assuming that everyone shares the same background and personality. For example, I didn’t have trouble interacting with the opposite sex, but a lot of people need to date to learn how to interact with the opposite sex in healthy ways, to learn more about yourself and what you’re looking for in a partner. The book didn’t factor that in.

You’re working on a documentary about this. Why? I’ve gone through different stages of my relationship with that book. I was proud and excited that it reached people and received positive feedback. It became a big part of my identity—it was the most successful thing I’d ever done. Then I got tired of being the guy who wrote IKDG. I moved on, started a family, pastored a church for 17 years.

Two years ago, I decided to step down from pastoring and attend Regent College in Vancouver, which created a space for me to listen and not feel like I have to have all the answers. There, fellow students told me how my book had negatively affected them. A woman wrote on Twitter, “Your book was used as a weapon against me.” I apologized, and later on my website asked for personal stories about IKDG’s impact. I got over 500 letters.

Reading through those letters was emotionally exhausting. I asked a professor to turn this into a guided study. I read all the letters, reread IKDG, and read various books on modern dating. (One of them was True Love Dates—I like that book.) The idea was to process what has happened since IKDG, how evangelicalism has approached dating and relationships, and my book’s role in it. What are the strengths and weaknesses of the purity movement?