Note: Each Friday, “On Faith & Culture” will feature an exclusive interview with a Christian thought leader or a voice of importance to the American Christian community.

Relationship expert Gary Chapman is the international bestselling author of The 5 Love Languages.

Dr. Gary Chapman, internationally respected marriage and family life expert and author of The Five Love Languages, has helped countless numbers of people communicate and understand love better. The consistent New York Times bestseller has sold more than five million copies, been translated into 38 languages, and has revolutionized relationships. This Valentine’s Day, we took a moment to reflect on the 20-year legacy of his revolutionary ideas.

JM: What’s your take on Valentine’s Day?

GC: Well, I think it gives an opportunity for the nation to focus on love, and in that sense, I think it’s positive. I know, there’s a lot of down sides, people say, but, I still think it’s nice that we have one day in a year that we can focus on expressing love to people, so I’m positive on Valentine’s Day.

JM: Looking back at your book The Five Love Languages, what do you think the lasting legacy of this monumental book will be?

GC: My hope is that it will continue to do, in the years ahead, what it has done in the past, and that is help couples learn how to connect with each other emotionally and keep emotional love alive in the marriage relationship. And, when I say marriage relationship you understand that I apply this to all human relationships, but I originally have that focus because my counseling has primarily been marriage counseling.

So many couples have said over the last number of years, “You know, we were struggling in our marriage, someone gave us the book, it was like the lights came on when we read it and we realized what had happened and how we’d missed each other emotionally. And we tried it, we tried speaking each other’s language and it changed the emotional climate of our marriage.”

So, my hope is that, that will continue to happen in the generations to come because I think it’s a timeless concept. We all desperately need to feel love, and if you’re married, the person you most like to love you is your spouse. And, if you feel loved, the world looks bright and if you don’t feel loved, the world can look pretty dark. So, I’m hoping that it will continue to help couples stay connected and also help parents learn how to effectively love their children and their teenagers.

JM: When was the original publication date of The Five Love Languages?

GC: You know that book has been out 20 years. It was published in 1992 and every year for 20 years, it has sold more than it did the year before, which is the opposite of most books. And it sold over 7 million copies in English and has been translated now into 49 languages around the world. And I think that’s because it does address this deep human need to feel loved.

JM: That book was the catalyst for several products and books. What are some of those?

GC: I have written over 30 books, and not all of them are about love languages, but we wrote the one for couples and I had a chapter on how it applies to children, and parents kept asking for more, so I teamed up with Dr. Ross Campbell who is a psychiatrist with 30 years’ experience with children and we wrote The Five Love Languages of Children. And then, I wrote The Five Love Languages of Teenagers because teenagers are a different breed and how do you effectively love them when they’re going through all of the emotional and physical changes?

And then singles; many single adults said, “I know you wrote your original book for married couples, but I read it and it helped in all of my relationships, so why don’t you write one for us?” So, I wrote The Five Love Languages Singles Edition, applying the concept to their parents because many young adults are estranged from their parents and how you can reconnect with them, apply it to their siblings, to their roommates, to their co-workers, to their dating partners.

And, then most recently I did the first children’s book I’ve ever done. It’s for children 4 to 8 years of age. The storyline is helping the children learn, at that young age, the concept of the five love languages – that mother has a love language, dad has a love language, and all the children have love languages. So it’s a fun book I’m hoping will help children get started off young with the concept. It’s called A Perfect Pet for Peyton: A 5 Love Languages Discovery Book.

How do you discover your love language?

The fastest and easiest way is to go online at fivelovelanguages.com and take the quiz, it’s free. But, you also can ask yourself three questions:

1. How do I typically express love and appreciation to other people? Because what I do for others is typically what I would like, so if I’m always patting people on the back or giving people hugs, then physical touch is probably my language. If I’m always giving words of affirmation, encouraging words, then words is probably my language. So observe yourself.

2. What do I complain about most often particularly in a marriage? This can be really helpful. If the spouse says, “We don’t spend any time together. We’re like two ships passing in the night,” they are telling you quality time is their love language. Or if they say, “I don’t think you would ever touch me, if I didn’t initiate it,” they are telling you physical touch is their language. Or if you go on a business trip and they say, “You didn’t bring me anything?” They’re telling you that gifts is their language. So, listen to your complaints.

3. What do you request most often? If you’re saying rather regularly, “Honey, can we take a walk after dinner tonight?” Or “You think we could get a weekend away?” You’re asking for quality time. So listen to what you request of your spouse.

The answer to those three things will give you your love language, and you can apply the same three questions to your spouse or anyone else for that matter and discover their love language.