For Dr. Ira Byock, the most important thing about dying is how you have lived your life.

Byock is best-known for "The Four Things That Matter Most: A Book About Living" (Atria Books Reissue, $24, 272 pp.), now in its 10th anniversary edition.

Byock, a long-time advocate for patients and families dealing with terminal illness, wrote the book because after two decades of talking about "dying well" he realized that he had stories to tell that "struck a nerve."

Bycock is this year's Dr. and Mrs. Max Littner Memorial Lecture Series for Bereavement speaker, presented by St. Luke's University Health Network, 7:30 p.m. May 14, Central Moravian Church, Main and Church streets, Bethlehem.

An endowment started by Wendy Littner Thomson, a licensed counselor and grief therapist in Bethlehem, in memory of her grandparents, funds the lecture series.

Thomson praised Byock's work as a perfect place to start to help remove the barriers to healthy relationships. "We are delighted he is coming.

"Dr. Byock was selected as this year's featured speaker because his message is basic to good mental health across the lifespan," Thomson stated in a press release.

"There is enormous value in getting our relationships 'current,' so when the time comes for us, or for a loved one to die, we will have the potential for a greater sense of peace."

Byock is Professor of Medicine at the Geisel School of Medicine at Dartmouth. He was Director of Palliative Medicine at Dartmouth-Hitchcock Medical Center, Lebanon, N.H., 2003 - '13.

What he learned by spending time with the dying is that, regardless of gender, ethnicity or country of origin, relationships are key to living and dying well.

Four simple statements can make all the difference in end-of-life relationships. They are: "Please forgive me," "I forgive you," "Thank-you" and "I love you."

Byock's book tells stories of people in a way to enable readers to imagine how they can apply the "Four Things" principle to their own lives.

Forgiveness is important to good health, but many misunderstand what this means.

"We think it is about exonerating someone who has hurt us. It's not about the other person at all. It is about us, about getting rid of the toxic badness in our own lives," Byock said in a recent teleconference interview.

The first person we need to forgive is our self. "Real forgiveness involves remembering and understanding that we are not perfect. Then you need to realize that the person who has wronged you is not perfect," he said.

Byock"s first book, "Dying Well" (1997), is a standard in palliative care. "The Four Things That Matter Most" (2004) is used in hospice counseling. "The Best Care Possible: A Physician's Quest to Transform Care Through the End of Life" (2012) addresses serious illness and dying in the United States.

Byock has appeared on NPR's "Talk of the Nation," "All Things Considered" and "Fresh Air;" American Public Media's " On Being," CBS's "60 Minutes," ABC's "Nightline" and PBS's "The News Hour."

Tickets: sluhn.org/irabyock, 1-866-STLUKES (1-866-785-8537), Moravian Book Store, 428 Main St., Bethlehem, where copies of Byock's book are available.