Fundamentalists were choking free thought in his secular nation, he wrote. But they couldn't silence it.
His friends warned him to be careful, to watch what he posted online. But Rahman dismissed those concerns, saying his Facebook profile page didn't even bear his picture. They don't even know what I look like, he told them.
On Monday, the 27-year-old Rahman fell victim to the same brazen act that killed Roy, hacked to death by two men with knives and meat cleavers just outside his house as he headed to work at a travel agency.
He was so maimed -- with wounds to his head, face and neck -- that police identified him through the voter identification card he was carrying.
His death was the second time in five weeks that someone was killed in Dhaka for online posts critical of Islam -- but they are hardly the only two who've paid a steep price.
In the last two years, several bloggers have died, either murdered or under mysterious circumstances.
"The despicable murder of Avijit Roy last month should have led authorities to step up protection measures for bloggers and others at risk. The killing of Washiqur Rahman today is another clear example of the Bangladeshi government's utter failure to ensure the safety of those at risk," said Abbas Faiz of Amnesty International
"How many more bloggers will have to be attacked before action is taken?"
As shocking as Rahman's death was, the reaction from some quarters was equally disturbing.
On his Facebook page (for which he picked a custom URL that translates to "unbeliever"), Rahman had posted a picture
with the hashtag #IamAvijit.
After his death, someone left a comment, "Now you are."
Another wrote, "I felt sorry when I first learned of your death. But then I saw what you wrote and I am not."
On his page, Rahman reposted a cartoon depicting Prophet Mohammed from the French satire magazine Charlie Hebdo. He wished a happy birthday to author Taslima Nasreen, who was forced to flee Bangladesh due to death threats from fundamentalists. And he "liked" a picture of sausages wrapped in crescent rolls that someone had captioned, "Pigs in burqas."
Posts threatening him were numerous.
"Get ready for the afterlife," one person commented on one of his posts.
"See you in hell," said another.
He used to write under the pseudonym "Stupid Man
" on a blog but switched to posting on Facebook after 2011.
There, he posted questions that critics of Islam often raised and then answered them. But he paired the answers in such a way that they highlighted the contradiction within Islam.
For example, one question asked what proof was there that the Quran was the word of God. The answer, "Mohammed said in his own words that the Quran is the word of God. Since Mohammed is the messenger of Allah, his claims are true."
He placed the question next to one that asked, "What is the proof that Mohammed was the messenger of Allah?"
The answer, "The Quran claims that Mohammed was the messenger of Allah. And since the Quran is God's word, its claims must be true."
Asif Mohiuddin, a blogger who himself was wounded by machete-wielding attackers in 2013 but survived, remembered Rahman as a great satirist.
"I named him the George Carlin of Bangladesh," he told the International Humanist and Ethical Union
. "He wanted with all his heart, a true secular country, where everyone can practice their freedom."
The irony is that the people who killed Rahman weren't even familiar with his writings; they were simply following orders, police said.
Of the three involved in the Monday morning attack, two were quickly caught by bystanders.
In confessions to police, the pair -- both students at Islamic schools -- said they didn't know what a blog was, nor had they seen Rahman's writing.
They said they were acting on orders from another person who told them killing Rahman was a religious duty, Police Commissioner Biplob Kumar Sarkar told reporters.
The third person is still to be apprehended.
That appears to be par for the course in the killings of bloggers in Bangladesh.
The only person arrested in the killing of Roy, the U.S. blogger, is Farabi Shafiur Rahman, who had called for his death in Facebook posts.
There has been no conviction in the January 2013 attack on Mohiuddin.
And no convictions in yet another case -- the hacking death of blogger Ahmed Rajib Haider, also in 2013.
"The Bangladeshi government must urgently establish accountability in this murder case and others," the Committee to Project Journalists said
after Rahman's death. "Otherwise the rest of the country's bloggers, commentators and journalists covering sensitive topics remain at grave risk of being attacked as well."
Bloggers, unlike political parties, aren't an organized force -- and that makes them an easy target for radicals, said Imran Sarker, who heads the Blogger and Online Activists Network in Bangladesh.
"They want peace, they talk of humanity. If you strike them with stones, they don't strike back. They try to reach you with flowers," he said. "So, if you want to sow fear and stifle progressive thought, they are easy to pick on."
But the deaths -- of Rahman, of Roy, of Haider -- have emboldened the movement, rather than chill them into silence.
"No one is cowering in their homes because this is happening. Because this has been happening regularly for a long time," he said. "We want to take the society forward. We know we have a lot left to accomplish."