The International Humanist and Ethical Union is calling for countries to abolish laws that protect religious sensibilities such as blasphemy laws.
The IHEU is a coalition of organizations that says it is the sole global umbrella organizsation embracing "humanist, atheist, rationalist, secularist, skeptic, laique, ethical cultural and freethought."
Following the Charlie Hebdo attacks in France, the groups that supports atheism says it is the time is right for countries to abolish laws that protect religious feelings, the BBC reports.
Blasphemy laws nevertheless remain popular in many parts of the world.
Ekmeleddin Ihsanoglu, secretary-general of the Organisation of Islamic Cooperation has said the international community should "come out of hiding from behind the excuse of freedom of expression," Reuters news agency has reported
At the Human Rights Council in Geneva, Western nations have argued against a universal blasphemy law that the OIC has sought for more than a decade.
The attacks on the staff of the Charlie Hebdo satirical magazine led to a massive response in defence of free speech - in France, but also across the world.
At the same time, intense protests against both the original cartoons, and the subsequent publication of another image of the Prophet Muhammad.
Sonja Eggerickx, the president of IHEU said the campaign is intended to support local people on the ground already working against blasphemy laws.
"The idea that 'insult' to religion is a crime is why humanists like Asif Mohiuddin are jailed in Bangladesh, is why secularists like Raif Badawi are being lashed in Saudi Arabia, is why atheists and religious minorities are persecuted in places like Afghanistan, Egypt, Pakistan, Iran, Sudan, and the list goes on," she said, the BBC reported.
Some Christian leaders have also argued for the necessity to allow blasphemy to exist because legislating against it can be used to persecute religious minorities as happens in countries such as the Middle East and Pakistan.