He urged Catholics of his diocese, and all those affected by the violence, to resist the temptation to seek revenge, calling such actions not only illegal, but also un-Christian.
"In the name of God, I appeal to my peace-loving people to please remain law abiding and not to take the law into their hands," he said. "Reprisal attacks are not the answer."
Nigerian President Muhammadu Buhari announced after the raid that his government "will not allow these attacks to continue."
Bishop Onah thanked Buhari for his order to police and military to bring the perpetrators to justice, but said that only "concrete actions" taken by local and federal government officials will "lead to the return of normalcy in the community."
"Some people predicted that Nigeria would be a failed State by the year 2015," he said.
"All of us heaved a sigh of relief after the general elections and the smooth handover last year. But any further delay in dealing with this and similar cases all over the country may lead those who made that prediction to affirm that its realization has only been delayed not avoided," the bishop added.
After visiting Nimbo the day after the attack, the Enugu State governor declared a two-day period of prayer and fasting to mourn for the community's loss.
Bishop Onah visited Nimbo April 28, telling those there that "God has not forsaken you. He is with you especially now that you are in need. We beg Him not to allow this kind of killings to happen again. We also beg Him to give our leaders good heart and spirit to prevent future re-occurrence. One thing I beg of you is this: do not look for trouble. Those of you that go to church knows that Jesus said you should forgive your offenders. Revenge will not take you anywhere; it will only complicate the situation more."
In the meantime, the Diocese of Nsukka will pray for the dead, care for the wounded survivors, and continue to call for an end to the violence in Nigeria.
"For decades (Nigerians) have continued to senselessly slaughter ourselves, squander our resources and destroy our environment," Bishop Onah wrote.
"We call on all to please stop this madness, so that, as a people, we may realize our full potentials for the benefit of all and to the glory of God."
(Story continues below)
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