Even in a so-called secular age, it takes courage and conviction to be an atheist
The writer GK Chesterton once wrote "When people choose not to believe in God, they do not hereafter believe in nothing, but they become capable of believing in anything".
I recalled this quote recently when I wrote about atheism in the context of the absence of a grace at the Belfast Lord Mayor's installation dinner, and my comments received a wide and lively response for, and against, my opinion.
It confirmed my view that, despite our so-called secular society, there is still a strong interest in religion in Northern Ireland.
However, atheism is also widespread, and it is a topic about which I have intended to write for some time.
This arose in my mind when I drove through east Belfast and saw a mural where one of the greatest atheists of this city was portrayed alongside other notable Belfast achievers who might well have been atheists, gay or lesbian, or heterosexuals, or indeed transgender.
To my mind, their sexuality does not matter, but we live in a world that is completely obsessed with sex, sexuality and gender.
It is sometimes a relief to read or hear about someone who does not use sexuality to define his or her identity and personality, but just gets on with life
One of these was the well-known atheist whose portrait is painted on that gable wall in east Belfast, and who later became one of the greatest religious writers in the history of Christianity.
I refer to CS Lewis, who was born and brought up in east Belfast, where his grandfather was the rector of St Mark's, Dundela. He was born into a home with deeply-held religious beliefs.
CS Lewis' atheism may have taken root after his adoring mother died when he was young, despite his fervent prayers to God for her survival.
It is also likely that Lewis' atheism further developed through the horrors of the First World War, in which he took part as a soldier. Such an experience is beyond our comprehension.
However, CS Lewis became a Christian during his distinguished academic career, and he remarked that on the night he kneeled down and accepted Christ into his life, he was "the most reluctant convert in all of England".
Despite this, he became one of the most famous sons of Belfast, and his Christian books still sell in large numbers all over the world.
Lewis encountered great grief when his beloved wife Joy died prematurely. This was made into the excellent film Shadowlands, based upon a successful stage play of the same name.
His brother, Warnie, had a drink problem, which was an added challenge, but CS Lewis never lost his faith again.
There's a memorial to him in east Belfast, and I would have preferred the name 'CS Lewis' on Belfast City Airport, rather than George Best's name, but that's another discussion for another day.
Despite the inspiring life and example of CS Lewis, I am regularly reminded of the challenge of atheism from a formerly well-known Ulster figure, now retired, who writes to me regularly about his lack of Christian belief.
His letters are well-argued, but I sometimes wonder why he, and other people I know, are so keen to tell me about their atheism. They do not annoy or disturb me because of their lack of religious belief. In fact, I respect anyone who is a genuine atheist, because it takes courage to stand at the deathbed of a loved one, or to face a medical prognosis of a terminal illness, and to declare "There's nothing beyond this".
I believe that a religious belief is deeply instinctive, as well as a search for meaning. When I look at a beautiful flower, or the innocence of a baby, I cannot believe that this is all coincidental. There has to be a higher Power, which many of us call God, behind all of this.
It is difficult to change people's views, particularly in later life, but my considered and intentionally helpful reply to an atheist who questions my faith is this: "If you are right, then neither of us will experience a life hereafter. However, if I am right, and there is a God, you will soon find out."
That usually ends our conversation.