For many people today, perhaps most, humanism is tantamount to atheism. The leading humanist organisations, which are atheistic, appear to have sealed the impression. They have lobbied for humanism to be taught as an alternative to faith in schools, and have won. Little wonder, then, that in religious circles, the H-word is almost a dirty word.

But if humanism makes believers feel uncomfortable, might it be because their institutions need to recover a human face?

Consider, say, religious institutions' attitude towards women and gay people - which is to say, the majority of human beings. It is characterised by equivocation at best, and very often outright denunciation. Or think of the concept of liberalism, another great humanist cause. It finds a religious articulation with Elizabeth I and her refusal to make "windows into men's souls". Her desire was to keep faith with human individuals, as God did when he made a covenant with the ancient people of Israel. In short, it's Biblical. So why do so many contemporary religious leaders seem wary of being thought a liberal?

In fact, perhaps contemporary humanism is actually a friend, only in the guise of a foe. What is it calling believers to remember and revive? Well, consider the history. Humanism was originally a religious movement that emerged in the late medieval period. There was Averroes, the great scholar of Islamic humanism, who wrote such a masterful commentary on Aristotle that for centuries in Europe he was known simply as "The Commentator". Or there is Maimonides, the Jewish philosopher. In his book, The Guide for the Perplexed, he argued that scientific and religious knowledge are intimately related, with advances in the former directly shaping the latter.

Moving into the Renaissance, the golden age for humanism, we encounter the Italian, Ficino. An enormously influential translator of Plato, he followed the ancient Athenian in describing how human love moves from the physical to the spiritual and so towards the divine. (Moreover, Ficino was not bothered by the fact that Plato thought of human love mostly in the guise of homosexual love.) Or again: perhaps the greatest humanist scholar of the period was the devout Christian, Erasmus. His book, Praise of Folly, pricked ecclesiastic pretensions with abandon. He might also be called the father of Biblical criticism: he posed brave questions about the authorship of books in the New Testament as early as 1516.

In the 20th century, humanism found new champions. Dietrich Bonhoeffer, who was killed by the Nazis, argued that Christianity should reject supernaturalism and otherworldliness to become non-religious and secular. He thought the modern world had come of age because it could be accountable to itself. Alternatively, the Catholic theologian, Karl Rahner, championed humanist approaches to doctrine at the second Vatican council. He wrote that when human beings are human in the fullest sense, they are "God's existence in the world".

It is hard to define humanism. Throughout the 20th century there have really been humanisms - Marxist, pragmatist and existentialist varieties, alongside the atheistic and religious. What they have in common is their anthropocentrism: the celebration of human science, human scholarship, human sentiments. Surely, people of faith should not shy from them today but continue to embrace them?

Philip Pullman has called on atheists to "not distort or misrepresent" religion. They should look to the best in the tradition, as they look to the best in science and philosophy. Well, people of faith need to respond to that challenge too, and keep their eyes focused on the best. The word "humanism" captures much of that.

Mark Vernon is the author of Teach Yourself Humanism (Hodder Education), with a foreword by Philip Pullman, published this month.

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