Before Joan Brown Campbell was ordained as a minister at age 50, she stayed home to raise three children. Today she is 80 and, after holding top positions with national religious groups and working with the likes of Nelson Mandela, Desmond Tutu and Martin Luther King Jr., she is still preaching, writing and scheduling lectures for her job at the Chautauqua Institution, a center for religion, the arts, education and recreation in Upstate New York. In 2010, she was awarded the Walter Cronkite Faith and Freedom Award, which promotes tolerance and public dialogue on controversial issues, and she published a book, “ Living into Hope: A Call to Spiritual Action for Such a Time as This .” Is facing death any easier after a lifetime of religious activism? “You are never ready to die,” said Campbell, a wavy-haired grandmother of eight. “You always think there is one more child to be born or one more wedding to go to. There’s one more funeral you think you ought to be there.” Campbell spoke with The Post recently about how a woman of the cloth deals with aging.

Has your faith changed as you have aged?

I have become much less concerned about the literal nature of the Bible — from whence it came, from how it came. I do believe the Bible, having lasted for 2,000 years or more, is a source of truth and guidance in our lives. It is a God-blessed document. I don’t doubt that. I am very much a God believer.

My daughter nearly died last year. She had knee surgery and got a terrible staph infection. She happens to be fine now, but we prayed. I am pretty convinced she came through this because people prayed for her and cared about her. In that sense I am very much a believer.

One of my great experiences in life is becoming friends with Carl Sagan. He would say, “You are so smart; why do you believe in God?” And I would say to him, “Carl, you are so smart; why don’t you believe in God?” We had great discussions about if I could prove there was God. Of course, you can’t.

What do you think happens after death?

I don’t believe personally that someone goes to hell. They probably live on, in some ways. I don’t see God as a punishing god in that particular way.

I don’t know what is beyond us. I would not want to deny that there is something beyond us, but we don’t know. Will I be reunited again with my father? Will I see my mother again? I don’t know.

I feel my mother. She is in my life in many ways. I will tell you a funny way. When I go to preach in Chautauqua, and it can be very hot in the summer, I always wear stockings. My mother would not have it that I was in front of the whole congregation without stockings. We may be gone, but we aren’t gone from hearts and minds of those left behind.

Do you think about death?

I have to preach a lot about the afterlife. I do a number of funerals. I always say at funerals what I truly believe: What will happen to us is not known to us.

What we do know is what we leave behind. If people believe that there is a heaven — and I am not saying I don’t believe in that — but if they believe there is some sort of real-estate view of heaven, I don’t try to straighten that out at the funeral. What I do say is: Regardless of the unknown, and we must say none of us know what happens to us after our bodily death . . . what we did when we were alive is very important.

Are you afraid of death?

I am not afraid of it. I am not in a rush to get there. I want to avoid it as long as I can and be healthy enough to enjoy life. As long as I am given that opportunity, I will take that.

I don’t feel I will disappear. I am already blessed with 80 years. I feel as though the people who I love and care about — and I am less concerned if my books live on; the older I get, the more my family is precious to me — they are me after I am gone.

I am not hooked to a magical something, but I do think there is a presence. I don’t know what it is. I don’t stew about it a lot. It would give me great comfort if there were actually a place. It would give me great comfort to know my children were all right and their children and their children, whom I will never see, but I don’t think there is.

My granddaughter asked me at my 75th birthday, “What does it feel like to have more years behind you than ahead of you?” That is a very profound question, because you might not be so happy with the years ahead of you if the years behind you were laden with all kinds of things you were sorry about.

The years behind me were good years. Many people feel they have a lot to fix in their years left. I don’t feel burdened with that.

What fears do you have?

One of my great fears is that at some point I will lose my capacity to read, and I am a reader.

I have macular degeneration. I am very fortunate that I have been a patient at the Cleveland Clinic since the beginning, and they were experimenting with vitamins as a way to deal with macular degeneration. My eyes have stayed the same. They haven’t changed. I can read quite well. I do find myself getting very tired when I read. I can use the big print.

The gift of the iPad is wonderful, as you can expand the letters. It is a huge gift, which I am sure they never thought about when they invented it, but it is a huge gift to people who have something like macular degeneration that affects so many older people.

I fear not working. I fear not having a clear mind. I value very much what work does for you and pushes you to do things. I think you always have work to do.

I worry I am not good at all the new electronics. I worry about not being in touch. I see people who do lose touch. I want to be present in my life. I am not afraid of people not liking me or making a mistake. I am more fearful I won’t have the capacity to be fully in touch with new ideas and younger people.

I fear loneliness that comes with age, where people are not physically able to do the things that keep them going.

I am very much kept alive by other people. I love people. I love having them in my house. I love having dinners. I had 14 people to Christmas dinner. To think I couldn’t cook a Christmas meal would be sad.

What else do you notice about getting older?

I just came back from three weeks in Africa, where I was out in the wild.

I will not say it isn’t harder as you get older. Your body doesn’t work as well. Walking over rocky roads is hard without having someone to hang on to. You have to give up on your pride that you can do it without anyone to help you. I think the most important thing to say is “Give me a hand. I really need someone to help me walking over this rocky road in the middle of the night in Africa.”

One thing you have to learn about aging is [that] not everything in your mind or your body is going to work exactly like it did when you were 50.

I take a lot of vitamins. I eat right. [But] I don’t exercise. I know I should do more of that.

Are there good things about aging?

The older people I know who are happy have something beyond themselves: a cause, a belief that they can get interested in. It takes you out of yourself, which is one of the gifts of a career. You get up in the morning and you go. You are confronted with things you can’t even know. It pushes you to be challenged.

The gift of age is that you are more secure in who you are. You know who are. You know what you have done. You are more free of ambition and wishing and wanting. The friendships you have are precious and important.

I have the privilege of doing the wedding of my oldest grandchild. Who ever got to live to marry a grandchild?