The cause of the widespread violence destroying thousands of people in Nigeria is nothing more than disobedience to God and the rule law.
If you don't fear God, then how can you fear man?

I have written and even over written on the causes and consequences of the Nigerian crisis and the articles have been popular discussions on Nairaland, Naijarules and other websites.
You can see some of them on the following links.

The Genesis Of The Crisis Of Terrorism In Nigeria - Politics - Nairaland
Corruption causes the leakages of power, undermines security and weakens leadership at all levels of human administration.
As corruption increases insecurity will become worse.
https://www.nairaland.com/651540/genesis-crisis-terrorism-nigeria

The Reign of Kleptocracy in Nigeria | Naijarules.com
www.naijarules.com › Forums › Hall 2 › News, Books, Art & Culture
Oct 30, 2006 - Orikinla New Member ... causes of these preventable catastrophic air disasters and know that corruption is the genesis of the Nigerian crisis.
The Reign of Kleptocracy in Nigeria. First, what is kleptocracy? May I quote from Wikipedia, the free encyclopedia. Kleptocracy (sometimes Cleptocracy) (root: Klepto+cracy = rule by thieves) is a pejorative, informal term for a government so corrupt that no pretense of honesty remains. In a kleptocracy the mechanisms of government are almost entirely devoted to taxing the public at large in order to amass substantial personal fortunes for the rulers and their cronies (collectively, kleptocrats), or to keep said rulers in power. Kleptocrats typically use money laundering and/or anonymous banking to protect and conceal their illegal gains.

Kleptocracies are by and large dictatorships or some other form of autocratic government, since democracy makes thievery more difficult to accomplish and conceal. Kleptocratic states consistently tend to be politically and socially unstable, while being stably kleptocratic. That is, the political governance of such states typically consists of one set of thieves displacing their predecessors by subversive or violent means.

The economies of kleptocracies tend to perform badly, as the systematic corruption engendered by kleptocratic governance means that the economy is subordinated to the interests of the kleptocrats. Kleptocrats realize that they have more to gain from taking a large share of a stable or shrinking pie than from a shrinking share of an increasing pie. Economies based on the extraction of natural resources (eg. diamonds and oil in a few prominent cases) can be particularly prone to kleptocracy, as the kleptocrats simply tax the Ricardian rent. Historically, the socio-political environment associated with colonial rule – in particular th...

From The Wasted Generation To The RE-TA-RDED ...
www.nairaland.com/917871/wasted-generation-re-ta-rded-generation
Apr 19, 2012 - 8 posts - ‎5 authors
Those who have been following the genesis of the Nigerian crisis since 1960 to date can understand the predicament of our social and political ...
Friday, October 21, 2005
The Unresolved Political Crisis In Nigeria and other Matters
http://nigeriantimes..com/2005/10/unresolved-political-crisis-in-nigeria.html

I am bringing up this issue again, because political amnesia is plaguing both the leaders and followers who seem to be now more confused by their partisan affiliations and loyalties than even during the past administration of former President Goodluck Jonathan.

Newly elected President Muhammadu Buhari is surrounded by wolves in sheep clothing and even the old foxes have joined the wolves and he is cornered by many interest groups who used their ill gotten riches to support his presidential campaign, because they had disagreements with his predecessor former President Goodluck Jonathan.

As I have stated before and will state it here again, that if armed robbers you knew were armed robbers gave you money and a ride in their stolen car to your destination, you cannot turn around and say you were not their accomplice and partner in crime, because you were a shareholder in their loot.
This is the political albatross of President Muhammadu Buhari.
And this is also the burden of majority of Nigerians who are partakers of the stolen billions of naira from the misappropriations of public funds and other corrupt practices from the messenger to the minister.
Majority of Nigerians are disobedient to the rule of law and the disobedience in public service is the cause of the widespread violence destroying thousands of lives and millions of properties in Nigeria.
The appointed political officers have failed to do their duties and their ministries are malfunctioning; from Lagos to Abuja and from the Niger Delta to Lake Chad.
Bizarre crimes of Kidnappings, human trafficking, armed robberies, rapes, murders and terrorist attacks are the consequences of the failures of public office holders.
The Nigerian police to the military, immigration and customs failed in their national security duties and comprised their positions to allow criminals and terrorists to infiltrate their ranks and files. That is why even the nomadic Hausa Fulani herdsmen have AK 47 guns and other firearms and both the Nigerian police and military failed to arrest them even right now.
How many of them have been arrested for illegal possession of arms and massacres of innocent people in the Middle Belt?
And these rebellious Hausa Fulani herdsmen are still rampaging and trespassing farmlands and villages outside their states of origin with impunity. But the Nigerian police and military forces have not arrested, arraigned or prosecuted anyone of them and thus encouraging them to continue their acts of lawlessness trespassing other states in Nigeria.
And is President Muhammadu Buhari addressing these terrible crimes?
NO.
He is busy looking the other way, saying he is fighting corruption.
How can he fight corruption when the robbers who gave him money and jolly ride in their stolen care are still walking free?
Dining and wining in their clubs, going to their churches and mosques and deceiving themselves and the masses who are also hypocrites who pretend to know God, but are far away from God as Lagos is far away from Jerusalem.
The larger populations of the so called Christians and Muslims are not holier than the corrupt political leaders who are not nation builders, but evil and greedy political opportunists, political contractors and political title chasers all competing against themselves in their dog eat dog political rat race.
They have turned Nigeria into a sociopolitical comedy of errors and a tragedy of horrors.

The curse of majority of Nigerians is disobedience to God.
God has created us in His image and after his likeness, but majority of us have chosen to behave and live like dogs. And that is why Nigeria is full of humans who have lost their humanity and are now ruled by their bestiality.

If we can behave and live in accordance and obedience to the appearance and countenance of the grace of God, and everyone doing his and her duty, the violence destroying Nigeria will be totally reduced or eradicated like in the other countries such as Switzerland and other civilized countries of the world where humans behave like civilized humans and not like animals without conscience and without shame as majority of Nigerians of today.