The first time they ever met was right after they both completed high school. Carol's sister had invited a group of friends to their home and Muriithi was one of them.
"It was the first time we had hosted guys in our home and we were amazed that they had such healthy appetites," says Carol with a laugh.
They met again in 1989 when registering for campus at University of Nairobi and signed up for common biochemistry classes. They became fast friends and could be seen walking to class together talking animatedly.
"Carol was easy to talk to and she wasn't trying to impress me. I could be really honest with her and we became best friends," says Muriithi.
Carol was attracted to Muriithi's gentle ways and authenticity. "We talked a lot which helped our friendship grow," says Carol.
At one time, Carol went away on a school trip for a week and Muriithi realised that he had grown very fond of her. "I was surprised to discover that I really missed her and was miserable without her."
He then decided that it was time to ask her out. Meanwhile Carol had been mulling on how to end the relationship.
"I had developed feelings for Muriithi, and I didn't want to slide into an undefined relationship. I had to end it. Fortunately he beat me to it and formally asked me to be his girlfriend. I said yes and we dated for the rest of our campus days," says Carol.
They made a decision from earlier on to restrict their dating life to group settings and public places. They steered off sex during courtship because as new Christians, they felt that it would quicken the relationship pace and give a false sense of intimacy.
"Focusing on building friendship as opposed to having sex during courtship helps to build a strong relational foundation and helps cope with the pressing demands of a career and raising children," says Carol, a trained marriage and family therapist.
After campus, the college sweethearts decided to both serve at Nairobi Chapel as interns. It was during a three-month mission trip to Swaziland that it dawned on Muriithi that he needed to propose to Carol.
"I made it very hard for her to turn me down," he says naughtily. "When I got back to Kenya I brought her so many gifts from South Africa, took her out for dinner at a posh restaurant and asked her to marry me," he continues.
They settled on a simple inexpensive wedding so that they could have a much more lavish honeymoon. "The value was in the celebration and not the money spent," says Carol. During their wedding in April 1994, Muriithi sang to Carol an original composition, accompanied by a live orchestra and choir made up of his friends.
Fast forward to 2017, Muriithi and Carol, the founders of Mavuno Church, play an active role in the Church's ministry. The church has campuses in Kenya, Rwanda, Uganda, Malawi, Germany and Zambia.
“Working together can be challenging especially when you both have different leadership styles. He sees the big picture and is a risk taker while I like to have clarity and I do not enjoy ambiguity. Working together has its perks though. It enhances our unity as we work towards the same purpose, and helps synchronize our annual calendars and leave days. To separate work and family life we do not discuss work at home past 6.00 pm," says Carol.
Tapping into their own marriage experience and training in theology and psychology, Muriithi and Carol have written a course called NDOA, designed to help couples prepare for marriage life. "When we were newly-weds, we wished we had an older couple with whom we could talk about real issues, and the NDOA marriage workshops provide a platform for couples to do this."
Muriithi appreciates various traits in Carol.
"She is my best friend, she knows me and we enjoy each other's presence, even when we're not actively talking. I like experiencing life with her so we travel together a lot. I appreciate her wisdom because she sees things very differently and is an incredible mum to our kids."
The couple is blessed with three children; Muini, Wairimu and Wanjau.
"We train and challenge them to live, read and think like leaders and take initiative,"says Carol. "We celebrate situations when they display positive leadership attributes," adds Muriithi.
Their advice to married couples is to work hard at their marriage.
"The one thing that outlasts your career and your parenting is your marriage. If you still have a great marriage when you're older, then everything else will have been worth it."