Azimio lawmakers now say that the Shakahola massacre could have been stopped, had state agencies tasked with the security of the country done their jobs.
They also want a public inquiry into the massacre opened.
In a statement, Minority leader Opiyo Wandayi said all those responsible should be punished, to prevent such negligence from occurring again.
"What happened in Kilifi is callous, painful and wrong. We believe it could have been prevented. We believe God allowed it to unravel to expose our hypocrisy as a nation," he said.
"This colossal failure of security, intelligence and community must be punished so that it does not happen again."
Wandayi said members of the National Government Administration Offices must be audited to find out how their laxity could have led to "this pain and shame".
"We must know who did or should have done what. We must audit the criminal justice system and its interactions with the main suspect and members of this cult," he said.
Azimio affirmed their support for tighter regulation of religious entities including churches, mosques, temples, and synagogues.
They said the government must come up with ways to stop deranged and criminal characters from destroying humanity in the name of religion.
The opposition also called for the speedy exhumation of the bodies believed to be buried in various parts of the vast 800-acre forest owned by controversial pastor Paul Mackenzie.
"It’s also baffling how the exhumation exercise should be moving at a snail’s pace despite the awesome machinery at the disposal of the State," Wandayi said.
