Dangers of being religious in a religious nation - BBC
Religious intolerance - in one of the most religious countries in Africa if not the world - is one of the issues dominating debates.
It is rare to find a Nigerian who is not devout in a nation that is roughly divided into a mainly Muslim north and a largely Christian south.
The constitution guarantees religious freedom - the country has no official religion and none of its 36 states is allowed to adopt one. It also prohibits religious discrimination.
Yet many who live in areas where they are in a religious minority do feel discriminated against, and live in fear - and with good reason given the history of religious-based violence.
"We don't have freedom to worship. If you dress like a Muslim, you are in trouble. We are just hiding our religion in fear of not being attacked," Ibrahim Bello, a Muslim living in south-eastern Nigeria, told the BBC.
Obinna Nnadi, a Christian who once lived in northern Kaduna state felt similarly fearful: "I felt it was not safe to practise my religion there. I had to pack my family and leave."
Neither has much confidence in the authorities to clamp down on intolerance - and Mr Bello says attacks do not always make the news, except those involving the Islamist insurgency in the north-east in which both Muslims and Christians are attacked by militants.
This lack of faith in the political class to deal with such discrimination has become more heated as the governing All Progressive Congress (APC) has upset a cross-party tradition - in practice since the return to democracy in 1999 - of having both a Christian and a Muslim on the presidential ticket.
The incumbent president is Muhammadu Buhari, a northern Muslim, while his deputy is Yemi Osinbajo, a southern Christian.
But the APC ticket for 2023 has Bola Tinubu, a southern Muslim, with Kashim Shettima, a northern Muslim, as his running mate.
Some feel this could inflame tensions. The Armed Conflict Location and Event Data Project (Acled) has recorded that the average number of monthly incidents of violence targeting Christians has risen by more than 25% in the last year.
While Acled has not separately captured religion-linked attacks on Muslims - except for attacks by militant groups like Boko Haram - some told the BBC of their experiences, especially in the south-east, an area largely inhabited by members of the Igbo ethnic group.
Aisha Obi is an Igbo Muslim - a growing community. Some are converts, although the majority were born into the faith in the predominantly Christian region.
She said women were the prime targets because of their Islamic dress and were subject to a hostility born of the civil war that started in 1967 when Igbo leaders declared independence.
The secessionist rebellion ended in defeat but some wounds are yet to heal with resentment felt towards the Muslim Hausa-Fulani community from the north, which then dominated the government.
"They see you as a saboteur," Ms Obi told the BBC.
"Even inside a vehicle or on a motorcycle, they call you: 'Hausa person, who knows what they are carrying. It could be a bomb.' They feel Igbos are not supposed to be Muslims," she said.
There are frequent attacks on individuals and mosques in the region which the authorities do not take seriously, she says.
"They don't believe us. When we tell them, they accuse us of us wanting to cause religious war."
Rev Caleb Ahima, vice-president of the Christian Association of Nigeria (CAN), acknowledges that religious discrimination is a consequence of location.
"In some states like [north-eastern] Borno, Christian religious knowledge is not allowed to be taught. Christians are not given plots of land to build their churches," he said.
Segregation
Rifkatu Aniya, from Kaduna state which has large Christian and Muslim communities, said she had never felt safe since her Christian husband, a pastor, was killed in religious violence that erupted in 2000.
The state's main city, also called Kaduna, has since divided into Christian and Muslim areas, explains resident Emeka Okeiyi, which impacts on their religious freedom.
"I can't say I have any restriction to practising my faith in the southern part of the city," he said - but he knows of Christians in the Muslim northern suburbs who would not dare set up a church.
There are followers of African traditional religions who also say they face intolerance - especially from those who follow the dominant faiths.
Odinani, or Odinala, was the religion of the vast majority of people in eastern Nigeria before the introduction of Christianity - and is making a comeback with younger people.
Odinani follower Cletus Chukwuemeka Ogbodo says the idea of religious harmony as enshrined in Nigeria's constitution is in stark contrast to how people are treated.
Pastors burn down shrines. Pastors burn people's ancestral heritages down during 'crusades'," he says about Christian attacks on traditional places of worship.
If the government adhered to the constitutional provisions, it would come to the aid of people and prosecute the perpetrators, he said.
Inter-faith future?
There has been a long legal battle in Nigeria's biggest city, Lagos, which has seen fierce argument over religious freedom vs secular rights.
It ended this year when Nigeria's Supreme Court upheld a ruling that female Muslim students had the right to wear a head scarf to school.
For Ishaq Akintola, director of Muslim Rights Concern (Muric), it was a victory for Muslims in the south who regularly feel they are not treated fairly.
But for others like lawyer Malcolm Omirhobo, it went against the secular spirit of the constitution.
To make a point he attended court in a traditional outfit - including a beaded gourd necklace and had a white circle drawn in chalk around his right eye like a priest of African religions.
"My fight is for secularity to be the norm," he told the BBC.
When the authorities do intervene tangibly in religious affairs it can also lead to resentment.
To stop religious incitement in Kaduna state, a ban was imposed on preaching last year - limiting it to those who are licensed by a council made up of members of both faiths.
This infuriated some Christian religious leaders, who suggested it was an example of government overreach - in particular Pastor Johnson Suleman of the Omega Fire Ministry, who accused the governor when it was first proposed of wanting to "Islamise Kaduna" in a sermon that went viral.
But the inter-faith council may be a way to foster local understanding - and could be a blueprint for other states.
Some Muslim and traditional leaders in Kaduna are now joining evangelical worshippers on Sundays - as part of efforts to ease tensions before the polls.