In a letter to the American Atheists conference, Hitchens encouraged fellow unbelievers to remain united and to carry on the “secular revolution”.

“Our weapons are the ironic mind against the literal; the open mind against the credulous; the courageous pursuit of truth against the fearful and abject forces who would set limits to investigation (and who stupidly claim that we already have all the truth we need),” wrote Hitchens in the letter.

The American Atheists organisation held its national conference in Des Moines, Iowa, over the weekend to coincide with the Easter holidays.

In his message, the famous atheist shared honestly that he is currently having a “long argument” with the “specter of death” in which no one has ever won. But as the idea of death becomes more familiar, he said the “pleading for salvation, redemption and supernatural deliverance” becomes “more hollow and artificial”.

Instead of the “false consolations of religion”, which he equates with superstition, Hitchens said he places his trust in medical science and the support of friends and family.

In June 2010, Hitchens was diagnosed with esophageal cancer, which is now at stage 4. Ironically, one of the scientists that helped designed the experimental cancer treatment that Hitchens is using is none other than evangelical scientist Francis Collins, the director of the National Institutes of Health.

Last month in an interview with Telegraph Magazine, Hitchens praised Collins, with whom he has debated the existence of God, and said the two have a “wonderful relationship” despite their religious differences.

Collins even wrote in The Washington Post a special prayer for Hitchens where he said his prayer is not so much for a supernatural intervention but for a medical miracle for his atheist friend.

But despite Hitchens’ fondness of Collins, he didn’t have nice things to say about religion. In the same sentence, Hitchens described the face of religion as “nuclear-armed mullahs” and “insidious campaigns” to teach “pseudo-science” in US schools.

Rallying atheists to form a resistance against “this sinister nonsense”, the cancer-stricken unbeliever called on his fellow atheists to defend and uphold the separation of church and state. He concluded his letter with the line"Don’t keep the faith.”