If you miss the bliss that brought the two of you together, take heart: You can bring it back, say Heather Cardin and Susanne Alexander, Baha’is who have been friends since they were teens.

Coincidentally, both have written books that help couples rekindle the light in their relationships.

Heather Cardin “Marriage takes hard work, a commitment to set out on the journey together and the conviction that the union is worth preserving,” says Ms. Cardin, a writer and college instructor in Quebec, and author of Partners in Spirit: What Couples Say About Marriages That Work.

Her friend agrees that throwing in the towel too soon is not the way to go: “It’s disturbingly common to hear people comment that divorce is almost inevitable, while at the same time couples dream of being the exception,” says Ms. Alexander, who, with her husband, Craig Farnsworth, runs the Marriage Transformation Project.

Based in Cleveland, the project offers workshops, coaching and written materials that emphasize character. For instance, says Ms. Alexander, reinforcing truthfulness, responsibility and faithfulness can improve your marriage, while ignoring these traits can cause serious problems.

The couple’s program is based on the Baha'i Faith’s view of marriage, which Abdu'l-Baha summarized in the following statement:

“The true marriage of Baha’is is this, that husband and wife should be united both physically and spiritually, that they may ever improve the spiritual life of each other, and may enjoy everlasting unity throughout all the worlds of God.”

Ms. Alexander and her husband offer couples a variety of communications exercises in their workshops and books, which include Marriage Can Be Forever – Preparation Counts!, Can We Dance? Learning the Steps for a Fulfilling Relationship and Pure Gold: Encouraging Character Qualities in Marriage. And if you need a break from the serious side of relationship and marriage work, she offers the lighter side with a new cartoon book, A Perfectly Funny Marriage.

Susanne AlexanderWhen times are rocky, says Ms. Cardin, who interviewed close to 40 couples for her book, “sometimes you need to wait it out, sometimes you need to talk it out and sometimes you have to stop analyzing it all the time and just work it. Happily married couples will tell you that keeping a marriage intact takes discipline, and that they exercise it because they’re in it for the long haul.”

Ms. Alexander says couples can achieve unity by acting and speaking respectfully to each other, among other practices.

“Think of unity as a garden of flowers,” she says, “where each one can be different in color or fragrance, yet blend as a whole. Unity is something greater than what can happen separately. That’s what marriage is all about.”