The senior pastor of Jesus House, in London, said some churches were too focused on trying to make Jesus and the cross palatable and acceptable to 21st century society.
"Thank God for advances in theology, thank God for thinkers in the church, thank God for churches that have to be seeker-friendly and all these other nice terms.
"But it seems that the more seeker-friendly we get, the less of Jesus we get so when people come to church they are not sure whether they are in church or at a gathering where someone is giving a motivational speech and the power is not in motivational speaking. The power is in Jesus," he said.
Irukwu made the comments in an address to the General Assembly of the Baptist Union of Great Britain (BUGB) last night.
Thousands of Baptists from across the UK gathered in London over the weekend for the General Assembly, which also celebrated 400 years since the founding of the first British Baptist church.
The weekend was spent trying to discern God's vision for the church going forward.
Irukwu, whose church belongs to the Redeemed Christian Church of God (RCCG), said the template for the future could be found in the past, in the early church.
The early Christians, he said, understood complete submission to the Holy Spirit and were not ashamed of the Gospel.
"We are not called to convince. We are called to declare and proclaim. Let the Holy Spirit do the work of convincing. We are just called to declare and proclaim," he said to applause.
Reflecting on the source of the early church's phenomenal growth, Irukwu said they were a community of grace and power.
He pointed to their lifestyle of prayer and the way in which they were completely united in the task of sharing the Gospel.
"They prayed for everything and about everything. They actually believed that God answers prayers.
"Maybe if the church in the United Kingdom became a praying church again, we would see a move of the Spirit of God.
"I dare say that we are a lot more in number than they were and if we can get ourselves praying, we can certainly get God moving in the land."
Irukwu suggested that Christians needed to learn to give sacrificially in their finances, not only to their own local churches but to the church's central administration.
He said the early church modelled the principle of the believers giving to the apostles and that in some situations, the church leadership was in a better position to distribute funds for the benefit of others.
He pointed to the example of the Festival of Life, the RCCG's flagship event in the UK, saying that it would not be possible without the giving of RCCG members.
The festival brings around 40,000 people to pray through the night in London each year. A second Festival of Life is taking place this year in Scotland on 20 July.
"The Gospel, with all our good intentions, is not going anywhere without money," he said.
"Some of my brothers have abused the prosperity gospel but you don't throw the baby out with the bath water.
"If you don't teach people about giving they will not give because they don't know.
"Maybe we need to start talking a bit more about giving and giving sacrificially in a biblical way, to encourage the church to give more."
He encouraged the church not to be discouraged in the face of "aggressive secularism" but to hold onto the vision of revival in our lifetime.
The church's efforts may lead to persecution but he said this was "part of the course" of being a Christian and a "badge of honour".
"One day, the sound of worship is going to resound from our cathedrals again and the church of the UK is going to become one church," he said.