Josh Harris, author of 'I Kissed Dating Goodbye' apologizes, will re-evaluate his book

The best-selling author of Christian book "I Kissed Dating Goodbye" dissuaded millions from dating and sex before marriage, but now apologizes for what his book might have caused.

Pastor Joshua Harris, who wrote the influential book on Christian dating when he was only 21, said he's re-thinking the lessons imparted on his 1997 book after soliciting messages from readers on how the book's affected them.

According to Slate, the former lead pastor of Covenant Life Church already received more than 300 responses and personally responded to critics on Twitter as well as talked with them on the phone.

Featured in the image is Pastor Joshua Harris | Josh Harris official website/Kristen Leigh

Elizabeth Ester, the author of "Girl at the End of the WorldandSpiritual Sobriety," tweeted May 10 that she never went to prom because of Fundamentalism.

"@elizabethesther I'm sorry. And I'm planning to dig into that in the next year or two. Again, I'd love to chat," Harris tweeted back.

Harris' personal responses unleashed a series of conversations from a group of critics and even resulted with a hashtag #KissShameBye for aggrieved readers who want to vent out.

"Part of the reason this has been so hard for me is that I have so much of my identity tied up in these books. It's what I'm known for," Harris told Slate in an interview.

"It's like, well, crap, is the biggest thing I've done in my life this really huge mistake?" he added.

The prominent Christian celebrity, now 41 with three kids – two of them now in their teens – in his 17 years of marriage, wrote that Christians should veer from traditional dating as this only leads to divorce and espoused abstinence.

Yet now, 19 years later, Harris admits that he was "very speculative" when he wrote the book, owing to his lack of experience in personal relationships back then and that it didn't help when readers attached to his book as a "rule book" or a "formula," which he claimed was not his intention.

"And I just don't think that's the way life works," he told NPR's Rachel Martin early last month. "I don't think that's the way the life of faith works ... And I'm - I think that that's part of the problem with my book."